diff --git a/src/dimension.h b/src/dimension.h
index 4e803682d3..bf42106de0 100644
--- a/src/dimension.h
+++ b/src/dimension.h
@@ -25,6 +25,12 @@ public:
 	/// initialize data
 	Dimension(int w, int a, int d) : wid(w), asc(a), des(d) {}
 
+	Dimension & operator=(Dimension const & dim) {
+		wid = dim.wid;
+		asc = dim.asc;
+		des = dim.des;
+		return *this;
+	}
 	/// glue horizontally
 	void operator+=(Dimension const & dim);
 	/// set to empty box
@@ -66,7 +72,14 @@ public:
 inline
 bool operator==(Dimension const & a, Dimension const & b)
 {
-	return a.wid == b.wid && a.asc == b.asc && a.des ==b.des ;
+	return a.wid == b.wid && a.asc == b.asc && a.des == b.des ;
+}
+
+
+inline
+bool operator!=(Dimension const & a, Dimension const & b)
+{
+	return a.wid != b.wid || a.asc != b.asc || a.des != b.des ;
 }
 
 
diff --git a/src/insets/inset.h b/src/insets/inset.h
index 7832a32017..a6f6a05a1b 100644
--- a/src/insets/inset.h
+++ b/src/insets/inset.h
@@ -56,8 +56,6 @@ public:
 protected:
 	///
 	InsetOld(InsetOld const & in);
-	///
-	mutable Dimension dim_;
 
 private:
 	InsetOld & operator=(InsetOld const &) const;
diff --git a/src/insets/insetbase.h b/src/insets/insetbase.h
index b69bbbde01..f0aa1d4903 100644
--- a/src/insets/insetbase.h
+++ b/src/insets/insetbase.h
@@ -12,9 +12,10 @@
 #ifndef INSETBASE_H
 #define INSETBASE_H
 
-#include "support/docstream.h"
-
 #include "changes.h"
+#include "dimension.h"
+
+#include "support/docstream.h"
 
 #include <memory>
 #include <vector>
@@ -103,7 +104,8 @@ public:
 	virtual InsetBase * editXY(LCursor & cur, int x, int y);
 
 	/// compute the size of the object returned in dim
-	virtual void metrics(MetricsInfo & mi, Dimension & dim) const = 0;
+	/// \retval true if metrics changed.
+	virtual bool metrics(MetricsInfo & mi, Dimension & dim) const = 0;
 	/// draw inset and update (xo, yo)-cache
 	virtual void draw(PainterInfo & pi, int x, int y) const = 0;
 	/// draw inset selection if necessary
@@ -443,6 +445,9 @@ protected:
 	 *  \sa getStatus
 	 */
 	virtual void doDispatch(LCursor & cur, FuncRequest & cmd);
+
+	/// Cached dimensions of the inset.
+	mutable Dimension dim_;
 private:
 	virtual std::auto_ptr<InsetBase> doClone() const = 0;
 };
diff --git a/src/insets/insetbox.C b/src/insets/insetbox.C
index c26131e21e..e5be700ae4 100644
--- a/src/insets/insetbox.C
+++ b/src/insets/insetbox.C
@@ -169,13 +169,15 @@ void InsetBox::setButtonLabel()
 }
 
 
-void InsetBox::metrics(MetricsInfo & m, Dimension & dim) const
+bool InsetBox::metrics(MetricsInfo & m, Dimension & dim) const
 {
 	MetricsInfo mi = m;
 	if (params_.inner_box || params_.special != "width")
 		mi.base.textwidth = params_.width.inPixels(m.base.textwidth);
 	InsetCollapsable::metrics(mi, dim);
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetbox.h b/src/insets/insetbox.h
index 00a69ca455..55ad9237dc 100644
--- a/src/insets/insetbox.h
+++ b/src/insets/insetbox.h
@@ -72,7 +72,7 @@ public:
 	///
 	void setButtonLabel();
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	/// show the Box dialog
 	bool showInsetDialog(BufferView * bv) const;
 	///
diff --git a/src/insets/insetcaption.C b/src/insets/insetcaption.C
index 482642f94a..ff747d6954 100644
--- a/src/insets/insetcaption.C
+++ b/src/insets/insetcaption.C
@@ -119,7 +119,7 @@ void InsetCaption::setLabel(LCursor & cur) const
 }
 
 
-void InsetCaption::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetCaption::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	mi.base.textwidth -= 2 * TEXT_TO_INSET_OFFSET;
 	LCursor cur = mi.base.bv->cursor();
@@ -135,7 +135,9 @@ void InsetCaption::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des += TEXT_TO_INSET_OFFSET;
 	dim.wid += 2 * TEXT_TO_INSET_OFFSET;
 	mi.base.textwidth += 2 * TEXT_TO_INSET_OFFSET;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetcaption.h b/src/insets/insetcaption.h
index d60718c128..310b0e0fd1 100644
--- a/src/insets/insetcaption.h
+++ b/src/insets/insetcaption.h
@@ -43,7 +43,7 @@ public:
 	///
 	bool descendable() const { return true; }
 	///
-	virtual void metrics(MetricsInfo & mi, Dimension & dim) const;
+	virtual bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	virtual void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetcharstyle.C b/src/insets/insetcharstyle.C
index 6d953726c8..3778ffda97 100644
--- a/src/insets/insetcharstyle.C
+++ b/src/insets/insetcharstyle.C
@@ -139,7 +139,7 @@ void InsetCharStyle::read(Buffer const & buf, LyXLex & lex)
 }
 
 
-void InsetCharStyle::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetCharStyle::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	LyXFont tmpfont = mi.base.font;
 	getDrawFont(mi.base.font);
@@ -168,9 +168,11 @@ void InsetCharStyle::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des += TEXT_TO_INSET_OFFSET;
 	dim.wid += 2 * TEXT_TO_INSET_OFFSET;
 	mi.base.textwidth += 2 * TEXT_TO_INSET_OFFSET;
-	dim_ = dim;
 	if (params_.show_label)
-		dim_.des += ascent();
+		dim.des += ascent();
+	bool const changed = dim_ != dim;
+	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetcharstyle.h b/src/insets/insetcharstyle.h
index 404e44ad40..34b910472f 100644
--- a/src/insets/insetcharstyle.h
+++ b/src/insets/insetcharstyle.h
@@ -68,7 +68,7 @@ public:
 	///
 	void read(Buffer const & buf, LyXLex & lex);
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo &, int, int) const;
 	///
diff --git a/src/insets/insetcollapsable.C b/src/insets/insetcollapsable.C
index 3d4434aa79..a2502a0dae 100644
--- a/src/insets/insetcollapsable.C
+++ b/src/insets/insetcollapsable.C
@@ -132,7 +132,7 @@ Dimension InsetCollapsable::dimensionCollapsed() const
 }
 
 
-void InsetCollapsable::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetCollapsable::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	autoOpen_ = mi.base.bv->cursor().isInside(this);
 	mi.base.textwidth -= 2 * TEXT_TO_INSET_OFFSET;
@@ -162,7 +162,9 @@ void InsetCollapsable::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des += TEXT_TO_INSET_OFFSET;
 	dim.wid += 2 * TEXT_TO_INSET_OFFSET;
 	mi.base.textwidth += 2 * TEXT_TO_INSET_OFFSET;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetcollapsable.h b/src/insets/insetcollapsable.h
index 539d1c78c9..82bae54483 100644
--- a/src/insets/insetcollapsable.h
+++ b/src/insets/insetcollapsable.h
@@ -46,7 +46,7 @@ public:
 	///
 	void write(Buffer const &, std::ostream &) const;
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetcommand.C b/src/insets/insetcommand.C
index 7fdedd2c80..3a7d50aa02 100644
--- a/src/insets/insetcommand.C
+++ b/src/insets/insetcommand.C
@@ -46,7 +46,7 @@ InsetCommand::~InsetCommand()
 }
 
 
-void InsetCommand::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetCommand::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (updateButtonLabel_) {
 		updateButtonLabel_ = false;
@@ -54,7 +54,9 @@ void InsetCommand::metrics(MetricsInfo & mi, Dimension & dim) const
 			       editable() != NOT_EDITABLE);
 	}
 	button_.metrics(mi, dim);
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetcommand.h b/src/insets/insetcommand.h
index 2b558aaeb4..c268f07e55 100644
--- a/src/insets/insetcommand.h
+++ b/src/insets/insetcommand.h
@@ -38,7 +38,7 @@ public:
 	///
 	~InsetCommand();
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetert.C b/src/insets/insetert.C
index b1698f5fb5..15e936c5d2 100644
--- a/src/insets/insetert.C
+++ b/src/insets/insetert.C
@@ -397,14 +397,16 @@ bool InsetERT::insetAllowed(InsetBase::Code /* code */) const
 }
 
 
-void InsetERT::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetERT::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	LyXFont tmpfont = mi.base.font;
 	getDrawFont(mi.base.font);
 	mi.base.font.realize(tmpfont);
 	InsetCollapsable::metrics(mi, dim);
 	mi.base.font = tmpfont;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetert.h b/src/insets/insetert.h
index cf573a1195..77f81aef22 100644
--- a/src/insets/insetert.h
+++ b/src/insets/insetert.h
@@ -63,7 +63,7 @@ public:
 	///
 	void validate(LaTeXFeatures &) const {}
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetexternal.C b/src/insets/insetexternal.C
index 6726d9859e..d0b0f86fe2 100644
--- a/src/insets/insetexternal.C
+++ b/src/insets/insetexternal.C
@@ -482,10 +482,12 @@ void InsetExternal::edit(LCursor & cur, bool)
 }
 
 
-void InsetExternal::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetExternal::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	renderer_->metrics(mi, dim);
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetexternal.h b/src/insets/insetexternal.h
index 6f175d787c..2e33880a20 100644
--- a/src/insets/insetexternal.h
+++ b/src/insets/insetexternal.h
@@ -116,7 +116,7 @@ public:
 	virtual EDITABLE editable() const { return IS_EDITABLE; }
 
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetfootlike.C b/src/insets/insetfootlike.C
index c071c3cfbc..8aef1d25bd 100644
--- a/src/insets/insetfootlike.C
+++ b/src/insets/insetfootlike.C
@@ -44,13 +44,15 @@ InsetFootlike::InsetFootlike(InsetFootlike const & in)
 }
 
 
-void InsetFootlike::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetFootlike::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	LyXFont tmpfont = mi.base.font;
 	mi.base.font = mi.base.bv->buffer()->params().getFont();
 	InsetCollapsable::metrics(mi, dim);
 	mi.base.font = tmpfont;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetfootlike.h b/src/insets/insetfootlike.h
index 6615a4655f..09e24ba420 100644
--- a/src/insets/insetfootlike.h
+++ b/src/insets/insetfootlike.h
@@ -27,7 +27,7 @@ public:
 	///
 	InsetFootlike(InsetFootlike const &);
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetgraphics.C b/src/insets/insetgraphics.C
index f5067fc64f..aaeb54e766 100644
--- a/src/insets/insetgraphics.C
+++ b/src/insets/insetgraphics.C
@@ -234,10 +234,12 @@ void InsetGraphics::edit(LCursor & cur, bool)
 }
 
 
-void InsetGraphics::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetGraphics::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	graphic_->metrics(mi, dim);
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetgraphics.h b/src/insets/insetgraphics.h
index 0d52776d8d..51ffe31ca2 100644
--- a/src/insets/insetgraphics.h
+++ b/src/insets/insetgraphics.h
@@ -35,7 +35,7 @@ public:
 	///
 	~InsetGraphics();
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	EDITABLE editable() const;
 	///
diff --git a/src/insets/insethfill.C b/src/insets/insethfill.C
index 25146edb54..1f20b3deab 100644
--- a/src/insets/insethfill.C
+++ b/src/insets/insethfill.C
@@ -32,12 +32,14 @@ std::auto_ptr<InsetBase> InsetHFill::doClone() const
 }
 
 
-void InsetHFill::metrics(MetricsInfo &, Dimension & dim) const
+bool InsetHFill::metrics(MetricsInfo &, Dimension & dim) const
 {
 	dim.wid = 3;
 	dim.asc = 3;
 	dim.des = 3;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insethfill.h b/src/insets/insethfill.h
index 3bfa98ffc3..51f5b59fa1 100644
--- a/src/insets/insethfill.h
+++ b/src/insets/insethfill.h
@@ -23,7 +23,7 @@ public:
 	///
 	InsetHFill();
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	docstring const getScreenLabel(Buffer const &) const;
 	///
diff --git a/src/insets/insetinclude.C b/src/insets/insetinclude.C
index f395ec700a..f374afcba3 100644
--- a/src/insets/insetinclude.C
+++ b/src/insets/insetinclude.C
@@ -648,7 +648,7 @@ InsetInclude::getBibfilesCache(Buffer const & buffer) const
 }
 
 
-void InsetInclude::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetInclude::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	BOOST_ASSERT(mi.base.bv && mi.base.bv->buffer());
 
@@ -673,7 +673,9 @@ void InsetInclude::metrics(MetricsInfo & mi, Dimension & dim) const
 	Box b(0, dim.wid, -dim.asc, dim.des);
 	button_.setBox(b);
 
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetinclude.h b/src/insets/insetinclude.h
index 65eee42452..4610e0ea10 100644
--- a/src/insets/insetinclude.h
+++ b/src/insets/insetinclude.h
@@ -35,7 +35,7 @@ public:
 	~InsetInclude();
 
 	/// Override these InsetButton methods if Previewing
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetlatexaccent.C b/src/insets/insetlatexaccent.C
index 3634bff900..e566acda70 100644
--- a/src/insets/insetlatexaccent.C
+++ b/src/insets/insetlatexaccent.C
@@ -242,7 +242,7 @@ void InsetLatexAccent::checkContents()
 }
 
 
-void InsetLatexAccent::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetLatexAccent::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	LyXFont & font = mi.base.font;
 	frontend::FontMetrics const & fm =	theFontMetrics(font);
@@ -273,7 +273,9 @@ void InsetLatexAccent::metrics(MetricsInfo & mi, Dimension & dim) const
 		docstring dcon(contents.begin(), contents.end());
 		dim.wid = fm.width(dcon) + 4;
 	}
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetlatexaccent.h b/src/insets/insetlatexaccent.h
index d09e221669..33446bd11a 100644
--- a/src/insets/insetlatexaccent.h
+++ b/src/insets/insetlatexaccent.h
@@ -36,7 +36,7 @@ public:
 	///
 	explicit InsetLatexAccent(std::string const & str);
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetline.C b/src/insets/insetline.C
index 87f0de3d20..9aa4d63e31 100644
--- a/src/insets/insetline.C
+++ b/src/insets/insetline.C
@@ -42,12 +42,14 @@ void InsetLine::write(Buffer const &, ostream & os) const
 }
 
 
-void InsetLine::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetLine::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	dim.asc = 3;
 	dim.des = 3;
 	dim.wid = mi.base.textwidth;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetline.h b/src/insets/insetline.h
index 67df1d33fd..8e5f6a7d10 100644
--- a/src/insets/insetline.h
+++ b/src/insets/insetline.h
@@ -25,7 +25,7 @@ public:
 
 	InsetBase::Code lyxCode() const { return InsetBase::LINE_CODE; }
 
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/insets/insetnewline.C b/src/insets/insetnewline.C
index c71d84eb28..302dda7769 100644
--- a/src/insets/insetnewline.C
+++ b/src/insets/insetnewline.C
@@ -41,13 +41,15 @@ void InsetNewline::write(Buffer const &, ostream & os) const
 }
 
 
-void InsetNewline::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetNewline::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	frontend::FontMetrics const & fm = theFontMetrics(mi.base.font);
 	dim.asc = fm.maxAscent();
 	dim.des = fm.maxDescent();
 	dim.wid = fm.width('n');
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetnewline.h b/src/insets/insetnewline.h
index 0a8353126d..aa6d2066dd 100644
--- a/src/insets/insetnewline.h
+++ b/src/insets/insetnewline.h
@@ -25,7 +25,7 @@ public:
 
 	InsetBase::Code lyxCode() const { return InsetBase::NEWLINE_CODE; }
 
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 
 	virtual void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/insets/insetpagebreak.C b/src/insets/insetpagebreak.C
index b82799d875..817c64d877 100644
--- a/src/insets/insetpagebreak.C
+++ b/src/insets/insetpagebreak.C
@@ -42,12 +42,14 @@ void InsetPagebreak::write(Buffer const &, ostream & os) const
 }
 
 
-void InsetPagebreak::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetPagebreak::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	dim.asc = defaultRowHeight();
 	dim.des = defaultRowHeight();
 	dim.wid = mi.base.textwidth;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetpagebreak.h b/src/insets/insetpagebreak.h
index b1def5c91a..57bb3b35f2 100644
--- a/src/insets/insetpagebreak.h
+++ b/src/insets/insetpagebreak.h
@@ -25,7 +25,7 @@ public:
 
 	InsetBase::Code lyxCode() const { return InsetBase::LINE_CODE; }
 
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/insets/insetquotes.C b/src/insets/insetquotes.C
index 46b9a99e05..ffbf0c4381 100644
--- a/src/insets/insetquotes.C
+++ b/src/insets/insetquotes.C
@@ -221,7 +221,7 @@ docstring const InsetQuotes::dispString(Language const * loclang) const
 }
 
 
-void InsetQuotes::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetQuotes::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	LyXFont & font = mi.base.font;
 	frontend::FontMetrics const & fm =
@@ -239,7 +239,9 @@ void InsetQuotes::metrics(MetricsInfo & mi, Dimension & dim) const
 		else
 			dim.wid += fm.width(',');
 	}
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetquotes.h b/src/insets/insetquotes.h
index 87e6a7b6b2..33a62e2f5c 100644
--- a/src/insets/insetquotes.h
+++ b/src/insets/insetquotes.h
@@ -74,7 +74,7 @@ public:
 	/// Direct access to inner/outer quotation marks
 	InsetQuotes(char_type c, quote_language l, quote_times t);
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 #if 0
diff --git a/src/insets/insetspace.C b/src/insets/insetspace.C
index 72dcca13b2..e7fc211fe5 100644
--- a/src/insets/insetspace.C
+++ b/src/insets/insetspace.C
@@ -48,7 +48,7 @@ InsetSpace::Kind InsetSpace::kind() const
 }
 
 
-void InsetSpace::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetSpace::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	frontend::FontMetrics const & fm =
 		theFontMetrics(mi.base.font);
@@ -75,7 +75,9 @@ void InsetSpace::metrics(MetricsInfo & mi, Dimension & dim) const
 			dim.wid = 10;
 			break;
 	}
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetspace.h b/src/insets/insetspace.h
index 02c88477e2..414e6e4171 100644
--- a/src/insets/insetspace.h
+++ b/src/insets/insetspace.h
@@ -56,7 +56,7 @@ public:
 	///
 	Kind kind() const;
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetspecialchar.C b/src/insets/insetspecialchar.C
index d22a51f90b..7ed1ea8489 100644
--- a/src/insets/insetspecialchar.C
+++ b/src/insets/insetspecialchar.C
@@ -42,7 +42,7 @@ InsetSpecialChar::Kind InsetSpecialChar::kind() const
 }
 
 
-void InsetSpecialChar::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetSpecialChar::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	frontend::FontMetrics const & fm =
 		theFontMetrics(mi.base.font);
@@ -61,7 +61,9 @@ void InsetSpecialChar::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.wid = fm.width(ds);
 	if (kind_ == HYPHENATION && dim.wid > 5)
 		dim.wid -= 2; // to make it look shorter
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetspecialchar.h b/src/insets/insetspecialchar.h
index 9a31348d67..26ee9612bd 100644
--- a/src/insets/insetspecialchar.h
+++ b/src/insets/insetspecialchar.h
@@ -48,7 +48,7 @@ public:
 	///
 	Kind kind() const;
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insettabular.C b/src/insets/insettabular.C
index 4990ce2936..979706645a 100644
--- a/src/insets/insettabular.C
+++ b/src/insets/insettabular.C
@@ -246,7 +246,7 @@ void InsetTabular::read(Buffer const & buf, LyXLex & lex)
 }
 
 
-void InsetTabular::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetTabular::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	//lyxerr << "InsetTabular::metrics: " << mi.base.bv << " width: " <<
 	//	mi.base.textwidth << "\n";
@@ -300,7 +300,9 @@ void InsetTabular::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = tabular.getAscentOfRow(0);
 	dim.des = tabular.getHeightOfTabular() - dim.asc;
 	dim.wid = tabular.getWidthOfTabular() + 2 * ADD_TO_TABULAR_WIDTH;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insettabular.h b/src/insets/insettabular.h
index a43e22e0bd..cb785f4b5e 100644
--- a/src/insets/insettabular.h
+++ b/src/insets/insettabular.h
@@ -60,7 +60,7 @@ public:
 	///
 	void write(Buffer const &, std::ostream &) const;
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insettext.C b/src/insets/insettext.C
index 0b843353a0..68067e44be 100644
--- a/src/insets/insettext.C
+++ b/src/insets/insettext.C
@@ -164,7 +164,7 @@ void InsetText::read(Buffer const & buf, LyXLex & lex)
 }
 
 
-void InsetText::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetText::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	//lyxerr << "InsetText::metrics: width: " << mi.base.textwidth << endl;
 	mi.base.textwidth -= 2 * border_;
@@ -176,7 +176,9 @@ void InsetText::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des += border_;
 	dim.wid += 2 * border_;
 	mi.base.textwidth += 2 * border_;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insettext.h b/src/insets/insettext.h
index 67128697d7..a2dd9f98a9 100644
--- a/src/insets/insettext.h
+++ b/src/insets/insettext.h
@@ -50,7 +50,7 @@ public:
 	///
 	void write(Buffer const & buf, std::ostream & os) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	/// draw inset selection
diff --git a/src/insets/insettheorem.C b/src/insets/insettheorem.C
index a7b9e2018e..4273ffecf6 100644
--- a/src/insets/insettheorem.C
+++ b/src/insets/insettheorem.C
@@ -69,12 +69,14 @@ auto_ptr<InsetBase> InsetTheorem::doClone() const
 	return result;
 }
 
-void InsetTheorem::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetTheorem::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	InsetCollapsable::metrics(mi, dim);
 	center_indent_ = (mi.base.textwidth - dim.wid) / 2;
 	dim.wid = mi.base.textwidth;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insettheorem.h b/src/insets/insettheorem.h
index 9a217d527f..2e1d8d59b1 100644
--- a/src/insets/insettheorem.h
+++ b/src/insets/insettheorem.h
@@ -30,7 +30,7 @@ public:
 	///
 	Inset::Code lyxCode() const { return Inset::THEOREM_CODE; }
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/insetvspace.C b/src/insets/insetvspace.C
index 64b9441d32..afb221aff2 100644
--- a/src/insets/insetvspace.C
+++ b/src/insets/insetvspace.C
@@ -116,7 +116,7 @@ int const arrow_size = 4;
 }
 
 
-void InsetVSpace::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetVSpace::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	int height = 3 * arrow_size;
 	if (space_.length().len().value() >= 0.0)
@@ -136,7 +136,9 @@ void InsetVSpace::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = height / 2 + (a - d) / 2; // align cursor with the
 	dim.des = height - dim.asc;         // label text
 	dim.wid = ADD_TO_VSPACE_WIDTH + 2 * arrow_size + 5 + w;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/insetvspace.h b/src/insets/insetvspace.h
index 350748b3f0..eb3a409c55 100644
--- a/src/insets/insetvspace.h
+++ b/src/insets/insetvspace.h
@@ -29,7 +29,7 @@ public:
 	///
 	~InsetVSpace();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/insets/render_base.h b/src/insets/render_base.h
index dbd7cec7f2..6a5dc57d3e 100644
--- a/src/insets/render_base.h
+++ b/src/insets/render_base.h
@@ -34,8 +34,9 @@ public:
 
 	virtual std::auto_ptr<RenderBase> clone(InsetBase const *) const = 0;
 
-	/// compute the size of the object returned in dim
-	virtual void metrics(MetricsInfo & mi, Dimension & dim) const = 0;
+	/// compute the size of the object returned in dim.
+	/// \retval true if the metrics has changed.
+	virtual bool metrics(MetricsInfo & mi, Dimension & dim) const = 0;
 	/// draw inset and update (xo, yo)-cache
 	virtual void draw(PainterInfo & pi, int x, int y) const = 0;
 
diff --git a/src/insets/render_button.C b/src/insets/render_button.C
index 6a833c744b..87172ddbc6 100644
--- a/src/insets/render_button.C
+++ b/src/insets/render_button.C
@@ -43,7 +43,7 @@ void RenderButton::update(docstring const & text, bool editable)
 }
 
 
-void RenderButton::metrics(MetricsInfo &, Dimension & dim) const
+bool RenderButton::metrics(MetricsInfo &, Dimension & dim) const
 {
 	LyXFont font(LyXFont::ALL_SANE);
 	font.decSize();
@@ -56,6 +56,10 @@ void RenderButton::metrics(MetricsInfo &, Dimension & dim) const
 		fm.rectText(text_, dim.wid, dim.asc, dim.des);
 
 	dim.wid += 4;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/insets/render_button.h b/src/insets/render_button.h
index fb4cfbf72f..244180431b 100644
--- a/src/insets/render_button.h
+++ b/src/insets/render_button.h
@@ -28,7 +28,7 @@ public:
 	std::auto_ptr<RenderBase> clone(InsetBase const *) const;
 
 	/// compute the size of the object returned in dim
-	virtual void metrics(MetricsInfo & mi, Dimension & dim) const;
+	virtual bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// draw inset and update (xo, yo)-cache
 	virtual void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/insets/render_graphic.C b/src/insets/render_graphic.C
index 9ab5697328..513b602d18 100644
--- a/src/insets/render_graphic.C
+++ b/src/insets/render_graphic.C
@@ -140,7 +140,7 @@ bool readyToDisplay(graphics::Loader const & loader)
 } // namespace anon
 
 
-void RenderGraphic::metrics(MetricsInfo & mi, Dimension & dim) const
+bool RenderGraphic::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	bool image_ready = displayGraphic(params_) && readyToDisplay(loader_);
 
@@ -175,7 +175,9 @@ void RenderGraphic::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.wid = std::max(50, font_width + 15);
 	}
 
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/render_graphic.h b/src/insets/render_graphic.h
index 498223521f..182e02f2d3 100644
--- a/src/insets/render_graphic.h
+++ b/src/insets/render_graphic.h
@@ -29,7 +29,7 @@ public:
 	std::auto_ptr<RenderBase> clone(InsetBase const *) const;
 
 	/// compute the size of the object returned in dim
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// draw inset
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/insets/render_preview.C b/src/insets/render_preview.C
index f46110f138..5badea260d 100644
--- a/src/insets/render_preview.C
+++ b/src/insets/render_preview.C
@@ -113,7 +113,7 @@ RenderPreview::getPreviewImage(Buffer const & buffer) const
 }
 
 
-void RenderPreview::metrics(MetricsInfo & mi, Dimension & dim) const
+bool RenderPreview::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	BOOST_ASSERT(mi.base.bv && mi.base.bv->buffer());
 
@@ -135,7 +135,9 @@ void RenderPreview::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.wid = 15 + theFontMetrics(font).width(stat);
 	}
 
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/insets/render_preview.h b/src/insets/render_preview.h
index bc9942132b..52bb7ffe04 100644
--- a/src/insets/render_preview.h
+++ b/src/insets/render_preview.h
@@ -52,7 +52,7 @@ public:
 	std::auto_ptr<RenderBase> clone(InsetBase const *) const;
 
 	/// Compute the size of the object, returned in dim
-	void metrics(MetricsInfo &, Dimension & dim) const;
+	bool metrics(MetricsInfo &, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/lyxtext.h b/src/lyxtext.h
index db04130328..f88de27317 100644
--- a/src/lyxtext.h
+++ b/src/lyxtext.h
@@ -116,8 +116,8 @@ public:
 	/// insert an inset at cursor position
 	void insertInset(LCursor & cur, InsetBase * inset);
 
-	/// compute text metrics
-	void metrics(MetricsInfo & mi, Dimension & dim);
+	/// compute text metrics.
+	bool metrics(MetricsInfo & mi, Dimension & dim);
 	/// draw text (only used for insets)
 	void draw(PainterInfo & pi, int x, int y) const;
 	/// draw textselection
diff --git a/src/mathed/InsetFormulaMacro.C b/src/mathed/InsetFormulaMacro.C
index 26cefd2f0e..fed292047b 100644
--- a/src/mathed/InsetFormulaMacro.C
+++ b/src/mathed/InsetFormulaMacro.C
@@ -124,14 +124,16 @@ string InsetFormulaMacro::prefix() const
 }
 
 
-void InsetFormulaMacro::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetFormulaMacro::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	//lyxerr << "InsetFormulaMacro: " << this << " -- " << &tmpl() << endl;
 	tmpl()->metrics(mi, dim);
 	dim.asc += 5;
 	dim.des += 5;
 	dim.wid += 10 + theFontMetrics(mi.base.font).width(prefix());
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/mathed/InsetFormulaMacro.h b/src/mathed/InsetFormulaMacro.h
index ad27ec2101..b32bd033c6 100644
--- a/src/mathed/InsetFormulaMacro.h
+++ b/src/mathed/InsetFormulaMacro.h
@@ -35,7 +35,7 @@ public:
 	/// constructs a mocro from its LaTeX definition
 	explicit InsetFormulaMacro(docstring const & s);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMath.h b/src/mathed/InsetMath.h
index 3cfc107e58..5aa419a098 100644
--- a/src/mathed/InsetMath.h
+++ b/src/mathed/InsetMath.h
@@ -84,7 +84,6 @@ class InfoStream;
 class MathMacroTemplate;
 class MathMacro;
 class MathPosFinder;
-class Dimension;
 class LCursor;
 class TextPainter;
 class TextMetricsInfo;
diff --git a/src/mathed/InsetMathAMSArray.C b/src/mathed/InsetMathAMSArray.C
index 18b3502ed8..55eeb7f159 100644
--- a/src/mathed/InsetMathAMSArray.C
+++ b/src/mathed/InsetMathAMSArray.C
@@ -79,12 +79,14 @@ char const * InsetMathAMSArray::name_right() const
 }
 
 
-void InsetMathAMSArray::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathAMSArray::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	ArrayChanger dummy(mi.base);
 	InsetMathGrid::metrics(mi, dim);
 	dim.wid += 14;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/mathed/InsetMathAMSArray.h b/src/mathed/InsetMathAMSArray.h
index b5f7255b37..64bf75c5bd 100644
--- a/src/mathed/InsetMathAMSArray.h
+++ b/src/mathed/InsetMathAMSArray.h
@@ -25,7 +25,7 @@ public:
 	///
 	InsetMathAMSArray(docstring const & name);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pain, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathArray.C b/src/mathed/InsetMathArray.C
index 83b94dcea6..54b1deaff6 100644
--- a/src/mathed/InsetMathArray.C
+++ b/src/mathed/InsetMathArray.C
@@ -80,12 +80,14 @@ auto_ptr<InsetBase> InsetMathArray::doClone() const
 }
 
 
-void InsetMathArray::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathArray::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	ArrayChanger dummy(mi.base);
 	InsetMathGrid::metrics(mi, dim);
 	dim.wid += 6;
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/mathed/InsetMathArray.h b/src/mathed/InsetMathArray.h
index b14f9b2e4e..0dd387dada 100644
--- a/src/mathed/InsetMathArray.h
+++ b/src/mathed/InsetMathArray.h
@@ -31,7 +31,7 @@ public:
 	/// convenience constructor from whitespace/newline separated data
 	InsetMathArray(docstring const &, docstring const & str);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBig.C b/src/mathed/InsetMathBig.C
index 49dbcd73c0..b0bcb7ebe6 100644
--- a/src/mathed/InsetMathBig.C
+++ b/src/mathed/InsetMathBig.C
@@ -62,14 +62,17 @@ double InsetMathBig::increase() const
 }
 
 
-void InsetMathBig::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBig::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	double const h = theFontMetrics(mi.base.font).ascent('I');
 	double const f = increase();
-	dim_.wid = 6;
-	dim_.asc = int(h + f * h);
-	dim_.des = int(f * h);
-	dim = dim_;
+	dim.wid = 6;
+	dim.asc = int(h + f * h);
+	dim.des = int(f * h);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathBig.h b/src/mathed/InsetMathBig.h
index 336c376067..5a983d19e7 100644
--- a/src/mathed/InsetMathBig.h
+++ b/src/mathed/InsetMathBig.h
@@ -27,7 +27,7 @@ public:
 	///
 	docstring name() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBinom.C b/src/mathed/InsetMathBinom.C
index 8597514000..564c21979d 100644
--- a/src/mathed/InsetMathBinom.C
+++ b/src/mathed/InsetMathBinom.C
@@ -45,7 +45,7 @@ int InsetMathBinom::dw() const
 }
 
 
-void InsetMathBinom::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBinom::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	ScriptChanger dummy(mi.base);
 	cell(0).metrics(mi);
@@ -54,7 +54,9 @@ void InsetMathBinom::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des = cell(1).height() + 4 - 5;
 	dim.wid = max(cell(0).width(), cell(1).width()) + 2 * dw() + 4;
 	metricsMarkers2(dim);
+	bool const changed = dim_ != dim;
 	dim_ = dim;
+	return changed;
 }
 
 
diff --git a/src/mathed/InsetMathBinom.h b/src/mathed/InsetMathBinom.h
index aba5364a7f..80ed9473f6 100644
--- a/src/mathed/InsetMathBinom.h
+++ b/src/mathed/InsetMathBinom.h
@@ -28,7 +28,7 @@ public:
 	///
 	void normalize(NormalStream &) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBoldSymbol.C b/src/mathed/InsetMathBoldSymbol.C
index 402648983d..989fac4d1a 100644
--- a/src/mathed/InsetMathBoldSymbol.C
+++ b/src/mathed/InsetMathBoldSymbol.C
@@ -33,13 +33,16 @@ auto_ptr<InsetBase> InsetMathBoldSymbol::doClone() const
 }
 
 
-void InsetMathBoldSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBoldSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	//FontSetChanger dummy(mi.base, "mathbf");
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
 	++dim.wid;  // for 'double stroke'
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathBoldSymbol.h b/src/mathed/InsetMathBoldSymbol.h
index cc50dae5e6..b9f7e78e5f 100644
--- a/src/mathed/InsetMathBoldSymbol.h
+++ b/src/mathed/InsetMathBoldSymbol.h
@@ -24,7 +24,7 @@ public:
 	///
 	InsetMathBoldSymbol();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBox.C b/src/mathed/InsetMathBox.C
index cdae7fdd89..4e1bce9dc5 100644
--- a/src/mathed/InsetMathBox.C
+++ b/src/mathed/InsetMathBox.C
@@ -48,12 +48,15 @@ void InsetMathBox::normalize(NormalStream & os) const
 }
 
 
-void InsetMathBox::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBox::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, "textnormal");
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathBox.h b/src/mathed/InsetMathBox.h
index 0591d29e0a..0bb2744d0a 100644
--- a/src/mathed/InsetMathBox.h
+++ b/src/mathed/InsetMathBox.h
@@ -31,7 +31,7 @@ public:
 	///
 	mode_type currentMode() const { return TEXT_MODE; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBoxed.C b/src/mathed/InsetMathBoxed.C
index 0f8d830284..4e15ce4ffe 100644
--- a/src/mathed/InsetMathBoxed.C
+++ b/src/mathed/InsetMathBoxed.C
@@ -38,11 +38,14 @@ auto_ptr<InsetBase> InsetMathBoxed::doClone() const
 }
 
 
-void InsetMathBoxed::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBoxed::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	metricsMarkers2(dim, 3); // 1 pixel space, 1 frame, 1 space
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathBoxed.h b/src/mathed/InsetMathBoxed.h
index 2764b8aa6c..930c7b3aa0 100644
--- a/src/mathed/InsetMathBoxed.h
+++ b/src/mathed/InsetMathBoxed.h
@@ -26,7 +26,7 @@ public:
 	///
 	void validate(LaTeXFeatures & features) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathBrace.C b/src/mathed/InsetMathBrace.C
index 03c7c567db..736a47250a 100644
--- a/src/mathed/InsetMathBrace.C
+++ b/src/mathed/InsetMathBrace.C
@@ -43,7 +43,7 @@ auto_ptr<InsetBase> InsetMathBrace::doClone() const
 }
 
 
-void InsetMathBrace::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathBrace::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	Dimension t;
@@ -52,7 +52,10 @@ void InsetMathBrace::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.des = max(cell(0).descent(), t.des);
 	dim.wid = cell(0).width() + 2 * t.wid;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathBrace.h b/src/mathed/InsetMathBrace.h
index fd673f36fe..3d581dc023 100644
--- a/src/mathed/InsetMathBrace.h
+++ b/src/mathed/InsetMathBrace.h
@@ -30,7 +30,7 @@ public:
 	/// we write extra braces in any case...
 	bool extraBraces() const { return true; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathCases.C b/src/mathed/InsetMathCases.C
index 46c09caa2c..d998c0e4e4 100644
--- a/src/mathed/InsetMathCases.C
+++ b/src/mathed/InsetMathCases.C
@@ -47,11 +47,16 @@ auto_ptr<InsetBase> InsetMathCases::doClone() const
 }
 
 
-void InsetMathCases::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathCases::metrics(MetricsInfo & mi, Dimension & dim) const
 {
+	dim = dim_;
 	InsetMathGrid::metrics(mi);
 	dim_.wid += 8;
+
+	if (dim_ == dim)
+		return false;
 	dim = dim_;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathCases.h b/src/mathed/InsetMathCases.h
index bae0cd7619..9f06cbdde8 100644
--- a/src/mathed/InsetMathCases.h
+++ b/src/mathed/InsetMathCases.h
@@ -25,7 +25,7 @@ public:
 	///
 	explicit InsetMathCases(row_type rows = 1u);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathChar.C b/src/mathed/InsetMathChar.C
index 18437ff6cf..aadcbc06cc 100644
--- a/src/mathed/InsetMathChar.C
+++ b/src/mathed/InsetMathChar.C
@@ -57,7 +57,7 @@ auto_ptr<InsetBase> InsetMathChar::doClone() const
 }
 
 
-void InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 #if 1
 	if (char_ == '=' && has_math_fonts) {
@@ -79,12 +79,16 @@ void InsetMathChar::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.wid += static_cast<int>(0.1667*em+0.5);
 #else
 	whichFont(font_, code_, mi);
-	mathed_char_dim(font_, char_, dim_);
+	mathed_char_dim(font_, char_, dim);
 	if (isBinaryOp(char_, code_))
 		width_ += 2 * theFontMetrics(font_).width(' ');
 	lyxerr << "InsetMathChar::metrics: " << dim << endl;
 #endif
 	width_ = dim.wid;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathChar.h b/src/mathed/InsetMathChar.h
index 140c16829b..8ee4e9c5cc 100644
--- a/src/mathed/InsetMathChar.h
+++ b/src/mathed/InsetMathChar.h
@@ -23,7 +23,7 @@ public:
 	///
 	explicit InsetMathChar(char_type c);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathColor.C b/src/mathed/InsetMathColor.C
index 55d9c656cb..32d7c29881 100644
--- a/src/mathed/InsetMathColor.C
+++ b/src/mathed/InsetMathColor.C
@@ -41,11 +41,14 @@ auto_ptr<InsetBase> InsetMathColor::doClone() const
 }
 
 
-void InsetMathColor::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathColor::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathColor.h b/src/mathed/InsetMathColor.h
index 71fada0473..5d23261a07 100644
--- a/src/mathed/InsetMathColor.h
+++ b/src/mathed/InsetMathColor.h
@@ -29,7 +29,7 @@ public:
 	/// Create a color inset from LaTeX color name
 	explicit InsetMathColor(bool oldstyle, docstring const & color);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// we write extra braces in any case...
 	/// FIXME Why? Are they necessary if oldstyle_ == false?
 	bool extraBraces() const { return true; }
diff --git a/src/mathed/InsetMathCommand.C b/src/mathed/InsetMathCommand.C
index 415c72b355..785017cc39 100644
--- a/src/mathed/InsetMathCommand.C
+++ b/src/mathed/InsetMathCommand.C
@@ -37,14 +37,17 @@ auto_ptr<InsetBase> CommandInset::doClone() const
 }
 
 
-void CommandInset::metrics(MetricsInfo & mi, Dimension & dim) const
+bool CommandInset::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (!set_label_) {
 		set_label_ = true;
 		button_.update(screenLabel(), true);
 	}
 	button_.metrics(mi, dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathCommand.h b/src/mathed/InsetMathCommand.h
index a95ec06c68..93c280aa38 100644
--- a/src/mathed/InsetMathCommand.h
+++ b/src/mathed/InsetMathCommand.h
@@ -27,7 +27,7 @@ public:
 	///
 	explicit CommandInset(docstring const & name);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathComment.C b/src/mathed/InsetMathComment.C
index 650c27f25d..857d721693 100644
--- a/src/mathed/InsetMathComment.C
+++ b/src/mathed/InsetMathComment.C
@@ -42,11 +42,14 @@ auto_ptr<InsetBase> InsetMathComment::doClone() const
 }
 
 
-void InsetMathComment::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathComment::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathComment.h b/src/mathed/InsetMathComment.h
index 184c7bd142..02986ed1f6 100644
--- a/src/mathed/InsetMathComment.h
+++ b/src/mathed/InsetMathComment.h
@@ -27,7 +27,7 @@ public:
 	///
 	explicit InsetMathComment(docstring const &);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathDFrac.C b/src/mathed/InsetMathDFrac.C
index e2c771e091..6a0a60f7a8 100644
--- a/src/mathed/InsetMathDFrac.C
+++ b/src/mathed/InsetMathDFrac.C
@@ -37,14 +37,17 @@ auto_ptr<InsetBase> InsetMathDFrac::doClone() const
 }
 
 
-void InsetMathDFrac::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathDFrac::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	cell(1).metrics(mi);
-	dim_.wid = max(cell(0).width(), cell(1).width()) + 2;
-	dim_.asc = cell(0).height() + 2 + 5;
-	dim_.des = cell(1).height() + 2 - 5;
-	dim = dim_;
+	dim.wid = max(cell(0).width(), cell(1).width()) + 2;
+	dim.asc = cell(0).height() + 2 + 5;
+	dim.des = cell(1).height() + 2 - 5;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathDFrac.h b/src/mathed/InsetMathDFrac.h
index 596f3f5522..3c62c8a664 100644
--- a/src/mathed/InsetMathDFrac.h
+++ b/src/mathed/InsetMathDFrac.h
@@ -24,7 +24,7 @@ public:
 	///
 	InsetMathDFrac();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathDecoration.C b/src/mathed/InsetMathDecoration.C
index 0d67122d85..846bac8faf 100644
--- a/src/mathed/InsetMathDecoration.C
+++ b/src/mathed/InsetMathDecoration.C
@@ -102,7 +102,7 @@ bool InsetMathDecoration::ams() const
 }
 
 
-void InsetMathDecoration::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathDecoration::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 
@@ -118,7 +118,10 @@ void InsetMathDecoration::metrics(MetricsInfo & mi, Dimension & dim) const
 	}
 
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathDecoration.h b/src/mathed/InsetMathDecoration.h
index 030836617f..d7019ae1e8 100644
--- a/src/mathed/InsetMathDecoration.h
+++ b/src/mathed/InsetMathDecoration.h
@@ -30,7 +30,7 @@ public:
 	///
 	void write(WriteStream & os) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void normalize(NormalStream & os) const;
 	///
diff --git a/src/mathed/InsetMathDelim.C b/src/mathed/InsetMathDelim.C
index b59ca12fea..f74b81e3bb 100644
--- a/src/mathed/InsetMathDelim.C
+++ b/src/mathed/InsetMathDelim.C
@@ -71,7 +71,7 @@ void InsetMathDelim::normalize(NormalStream & os) const
 }
 
 
-void InsetMathDelim::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathDelim::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	Dimension t;
@@ -84,10 +84,13 @@ void InsetMathDelim::metrics(MetricsInfo & mi, Dimension & dim) const
 		dw_ = 8;
 	if (dw_ < 4)
 		dw_ = 4;
-	dim_.wid = cell(0).width() + 2 * dw_ + 8;
-	dim_.asc = max(a0, d0) + h0;
-	dim_.des = max(a0, d0) - h0;
-	dim = dim_;
+	dim.wid = cell(0).width() + 2 * dw_ + 8;
+	dim.asc = max(a0, d0) + h0;
+	dim.des = max(a0, d0) - h0;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathDelim.h b/src/mathed/InsetMathDelim.h
index cc34e54980..ab94d85808 100644
--- a/src/mathed/InsetMathDelim.h
+++ b/src/mathed/InsetMathDelim.h
@@ -40,7 +40,7 @@ public:
 	///
 	mode_type currentMode() const { return MATH_MODE; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 
diff --git a/src/mathed/InsetMathDiff.C b/src/mathed/InsetMathDiff.C
index 8b74d26b26..47ee175654 100644
--- a/src/mathed/InsetMathDiff.C
+++ b/src/mathed/InsetMathDiff.C
@@ -48,9 +48,10 @@ void InsetMathDiff::normalize(NormalStream & os) const
 }
 
 
-void InsetMathDiff::metrics(MetricsInfo &, Dimension &) const
+bool InsetMathDiff::metrics(MetricsInfo &, Dimension &) const
 {
 	lyxerr << "should not happen" << endl;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathDiff.h b/src/mathed/InsetMathDiff.h
index 3dfc0b1864..02658add64 100644
--- a/src/mathed/InsetMathDiff.h
+++ b/src/mathed/InsetMathDiff.h
@@ -28,7 +28,7 @@ public:
 	///
 	void addDer(MathArray const & der);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMathDim.h b/src/mathed/InsetMathDim.h
index a88d2f545d..30f13eb20f 100644
--- a/src/mathed/InsetMathDim.h
+++ b/src/mathed/InsetMathDim.h
@@ -13,8 +13,6 @@
 #define MATH_DIMINSET_H
 
 #include "InsetMath.h"
-#include "dimension.h"
-
 
 namespace lyx {
 
@@ -38,10 +36,6 @@ public:
 
 	///
 	void setPosCache(PainterInfo const & pi, int x, int y) const;
-
-protected:
-	///
-	mutable Dimension dim_;
 };
 
 
diff --git a/src/mathed/InsetMathDots.C b/src/mathed/InsetMathDots.C
index 0d6c954b0f..5178aa6432 100644
--- a/src/mathed/InsetMathDots.C
+++ b/src/mathed/InsetMathDots.C
@@ -35,7 +35,7 @@ auto_ptr<InsetBase> InsetMathDots::doClone() const
 }
 
 
-void InsetMathDots::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathDots::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	mathed_char_dim(mi.base.font, 'M', dim);
 	dh_ = 0;
@@ -50,7 +50,10 @@ void InsetMathDots::metrics(MetricsInfo & mi, Dimension & dim) const
 	}
 	else if (key_->name == "ddots")
 		dh_ = dim.asc;
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathDots.h b/src/mathed/InsetMathDots.h
index 424a0f738a..86173a0b37 100644
--- a/src/mathed/InsetMathDots.h
+++ b/src/mathed/InsetMathDots.h
@@ -25,7 +25,7 @@ public:
 	///
 	explicit InsetMathDots(latexkeys const * l);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathEnv.C b/src/mathed/InsetMathEnv.C
index e86ec67b40..3a13320fcb 100644
--- a/src/mathed/InsetMathEnv.C
+++ b/src/mathed/InsetMathEnv.C
@@ -35,11 +35,14 @@ auto_ptr<InsetBase> InsetMathEnv::doClone() const
 }
 
 
-void InsetMathEnv::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathEnv::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathEnv.h b/src/mathed/InsetMathEnv.h
index 75252bb18a..49922d4cc9 100644
--- a/src/mathed/InsetMathEnv.h
+++ b/src/mathed/InsetMathEnv.h
@@ -32,7 +32,7 @@ public:
 	/// write normalized content
 	void normalize(NormalStream & ns) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void infoize(odocstream & os) const;
 
diff --git a/src/mathed/InsetMathExFunc.C b/src/mathed/InsetMathExFunc.C
index 4b9ba777cb..f74af99e0c 100644
--- a/src/mathed/InsetMathExFunc.C
+++ b/src/mathed/InsetMathExFunc.C
@@ -42,9 +42,13 @@ auto_ptr<InsetBase> InsetMathExFunc::doClone() const
 }
 
 
-void InsetMathExFunc::metrics(MetricsInfo & mi, Dimension & /*dim*/) const
+bool InsetMathExFunc::metrics(MetricsInfo & mi, Dimension & dim) const
 {
-	mathed_string_dim(mi.base.font, name_, dim_);
+	mathed_string_dim(mi.base.font, name_, dim);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathExFunc.h b/src/mathed/InsetMathExFunc.h
index 1dc39f6b8f..5f150eeab9 100644
--- a/src/mathed/InsetMathExFunc.h
+++ b/src/mathed/InsetMathExFunc.h
@@ -30,7 +30,7 @@ public:
 	///
 	InsetMathExFunc(docstring const & name, MathArray const & ar);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathExInt.C b/src/mathed/InsetMathExInt.C
index a349946a7e..8427723418 100644
--- a/src/mathed/InsetMathExInt.C
+++ b/src/mathed/InsetMathExInt.C
@@ -65,9 +65,10 @@ void InsetMathExInt::normalize(NormalStream & os) const
 }
 
 
-void InsetMathExInt::metrics(MetricsInfo &, Dimension &) const
+bool InsetMathExInt::metrics(MetricsInfo &, Dimension &) const
 {
 	lyxerr << "should not happen" << endl;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathExInt.h b/src/mathed/InsetMathExInt.h
index 50ea077f37..f1f51d45f4 100644
--- a/src/mathed/InsetMathExInt.h
+++ b/src/mathed/InsetMathExInt.h
@@ -29,7 +29,7 @@ public:
 	///
 	void symbol(docstring const &);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 
diff --git a/src/mathed/InsetMathFBox.C b/src/mathed/InsetMathFBox.C
index 7306c6ed61..71a9ec192d 100644
--- a/src/mathed/InsetMathFBox.C
+++ b/src/mathed/InsetMathFBox.C
@@ -43,12 +43,15 @@ InsetMath::mode_type InsetMathFBox::currentMode() const
 }
 
 
-void InsetMathFBox::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathFBox::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, "textnormal");
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim, 3); // 1 pixel space, 1 frame, 1 space
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathFBox.h b/src/mathed/InsetMathFBox.h
index 1cd2b9d17c..9e8e1a4575 100644
--- a/src/mathed/InsetMathFBox.h
+++ b/src/mathed/InsetMathFBox.h
@@ -26,7 +26,7 @@ public:
 	///
 	mode_type currentMode() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathFont.C b/src/mathed/InsetMathFont.C
index 7326b69817..dd66629c33 100644
--- a/src/mathed/InsetMathFont.C
+++ b/src/mathed/InsetMathFont.C
@@ -44,12 +44,15 @@ InsetMath::mode_type InsetMathFont::currentMode() const
 }
 
 
-void InsetMathFont::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathFont::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, key_->name);
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathFont.h b/src/mathed/InsetMathFont.h
index b83910523f..085ca65b56 100644
--- a/src/mathed/InsetMathFont.h
+++ b/src/mathed/InsetMathFont.h
@@ -34,7 +34,7 @@ public:
 	///
 	docstring name() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathFontOld.C b/src/mathed/InsetMathFontOld.C
index a78e4e77d2..21c8e17bd0 100644
--- a/src/mathed/InsetMathFontOld.C
+++ b/src/mathed/InsetMathFontOld.C
@@ -36,12 +36,15 @@ auto_ptr<InsetBase> InsetMathFontOld::doClone() const
 }
 
 
-void InsetMathFontOld::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathFontOld::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, key_->name.c_str());
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathFontOld.h b/src/mathed/InsetMathFontOld.h
index 7e44e08c9f..734fabc3e7 100644
--- a/src/mathed/InsetMathFontOld.h
+++ b/src/mathed/InsetMathFontOld.h
@@ -30,7 +30,7 @@ public:
 	/// we write extra braces in any case...
 	bool extraBraces() const { return true; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathFrac.C b/src/mathed/InsetMathFrac.C
index 714043d573..8d9fa33bc6 100644
--- a/src/mathed/InsetMathFrac.C
+++ b/src/mathed/InsetMathFrac.C
@@ -51,7 +51,7 @@ InsetMathFrac const * InsetMathFrac::asFracInset() const
 }
 
 
-void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FracChanger dummy(mi.base);
 	cell(0).metrics(mi);
@@ -66,7 +66,10 @@ void InsetMathFrac::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.des = cell(1).height() + 2 - 5;
 	}
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathFrac.h b/src/mathed/InsetMathFrac.h
index dc4ed0bf52..ae361f0b99 100644
--- a/src/mathed/InsetMathFrac.h
+++ b/src/mathed/InsetMathFrac.h
@@ -33,7 +33,7 @@ public:
 	///
 	explicit InsetMathFrac(Kind kind = FRAC);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathFrameBox.C b/src/mathed/InsetMathFrameBox.C
index 6636442967..a6c270b34e 100644
--- a/src/mathed/InsetMathFrameBox.C
+++ b/src/mathed/InsetMathFrameBox.C
@@ -34,7 +34,7 @@ auto_ptr<InsetBase> InsetMathFrameBox::doClone() const
 }
 
 
-void InsetMathFrameBox::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathFrameBox::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, "textnormal");
 	w_ = mathed_char_width(mi.base.font, '[');
@@ -43,7 +43,10 @@ void InsetMathFrameBox::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim += cell(1).dim();
 	dim += cell(2).dim();
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathFrameBox.h b/src/mathed/InsetMathFrameBox.h
index 2034e5b375..445bc1468e 100644
--- a/src/mathed/InsetMathFrameBox.h
+++ b/src/mathed/InsetMathFrameBox.h
@@ -24,7 +24,7 @@ public:
 	///
 	InsetMathFrameBox();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathGrid.C b/src/mathed/InsetMathGrid.C
index 7d52295604..46eed9db8e 100644
--- a/src/mathed/InsetMathGrid.C
+++ b/src/mathed/InsetMathGrid.C
@@ -471,10 +471,14 @@ void InsetMathGrid::metrics(MetricsInfo & mi) const
 }
 
 
-void InsetMathGrid::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathGrid::metrics(MetricsInfo & mi, Dimension & dim) const
 {
-	metrics(mi);
 	dim = dim_;
+	metrics(mi);
+	if (dim_ == dim)
+		return false;
+	dim = dim_;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathGrid.h b/src/mathed/InsetMathGrid.h
index f2fbcceb2e..b08ad54be5 100644
--- a/src/mathed/InsetMathGrid.h
+++ b/src/mathed/InsetMathGrid.h
@@ -97,7 +97,7 @@ public:
 	///
 	void metrics(MetricsInfo & mi) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension &) const;
+	bool metrics(MetricsInfo & mi, Dimension &) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathHull.C b/src/mathed/InsetMathHull.C
index 8ee9abe9ae..4f2f7c4366 100644
--- a/src/mathed/InsetMathHull.C
+++ b/src/mathed/InsetMathHull.C
@@ -283,7 +283,7 @@ bool InsetMathHull::previewState(BufferView * bv) const
 }
 
 
-void InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (previewState(mi.base.bv)) {
 		preview_->metrics(mi, dim);
@@ -291,8 +291,10 @@ void InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
 		dim.wid += 1;
 		if (display())
 			dim.des += displayMargin();
+		if (dim_ == dim)
+			return false;
 		dim_ = dim;
-		return;
+		return true;
 	}
 
 	FontSetChanger dummy1(mi.base, standardFont());
@@ -323,7 +325,10 @@ void InsetMathHull::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = max(dim.asc, asc);
 	dim.des = max(dim.des, des);
 
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathHull.h b/src/mathed/InsetMathHull.h
index 41123a4cc8..1df5ce128b 100644
--- a/src/mathed/InsetMathHull.h
+++ b/src/mathed/InsetMathHull.h
@@ -35,7 +35,7 @@ public:
 	///
 	mode_type currentMode() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathKern.C b/src/mathed/InsetMathKern.C
index b4ad79d2cc..b696a96b1d 100644
--- a/src/mathed/InsetMathKern.C
+++ b/src/mathed/InsetMathKern.C
@@ -43,12 +43,16 @@ auto_ptr<InsetBase> InsetMathKern::doClone() const
 }
 
 
-void InsetMathKern::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathKern::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	wid_pix_ = wid_.inPixels(0, mathed_char_width(mi.base.font, 'M'));
 	dim.wid = wid_pix_;
 	dim.asc = 0;
 	dim.des = 0;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathKern.h b/src/mathed/InsetMathKern.h
index 63c20d0008..218278de92 100644
--- a/src/mathed/InsetMathKern.h
+++ b/src/mathed/InsetMathKern.h
@@ -31,7 +31,7 @@ public:
 	///
 	explicit InsetMathKern(docstring const & wid);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathLefteqn.C b/src/mathed/InsetMathLefteqn.C
index b75c0da0a9..749bce7068 100644
--- a/src/mathed/InsetMathLefteqn.C
+++ b/src/mathed/InsetMathLefteqn.C
@@ -33,14 +33,17 @@ auto_ptr<InsetBase> InsetMathLefteqn::doClone() const
 }
 
 
-void InsetMathLefteqn::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathLefteqn::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	dim.asc += 2;
 	dim.des += 2;
 	dim.wid = 4;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathLefteqn.h b/src/mathed/InsetMathLefteqn.h
index cf0d41495d..aecffbfe6c 100644
--- a/src/mathed/InsetMathLefteqn.h
+++ b/src/mathed/InsetMathLefteqn.h
@@ -27,7 +27,7 @@ public:
 	///
 	docstring name() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathLim.C b/src/mathed/InsetMathLim.C
index 6e30133962..59c6aa3dcc 100644
--- a/src/mathed/InsetMathLim.C
+++ b/src/mathed/InsetMathLim.C
@@ -44,9 +44,10 @@ void InsetMathLim::normalize(NormalStream & os) const
 }
 
 
-void InsetMathLim::metrics(MetricsInfo &, Dimension &) const
+bool InsetMathLim::metrics(MetricsInfo &, Dimension &) const
 {
 	lyxerr << "should not happen" << endl;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathLim.h b/src/mathed/InsetMathLim.h
index bb6edd2ebb..af1480dd0c 100644
--- a/src/mathed/InsetMathLim.h
+++ b/src/mathed/InsetMathLim.h
@@ -26,7 +26,7 @@ public:
 	///
 	InsetMathLim(MathArray const & f, MathArray const & x, MathArray const & x0);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMathMBox.C b/src/mathed/InsetMathMBox.C
index 962ece1de0..9f70529010 100644
--- a/src/mathed/InsetMathMBox.C
+++ b/src/mathed/InsetMathMBox.C
@@ -50,11 +50,14 @@ auto_ptr<InsetBase> InsetMathMBox::doClone() const
 }
 
 
-void InsetMathMBox::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathMBox::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	text_.metrics(mi, dim);
 	metricsMarkers2(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathMBox.h b/src/mathed/InsetMathMBox.h
index cc621b71c7..e1c34e8acf 100644
--- a/src/mathed/InsetMathMBox.h
+++ b/src/mathed/InsetMathMBox.h
@@ -26,7 +26,7 @@ public:
 	///
 	explicit InsetMathMBox(BufferView & bv);
 	/// this stores metrics information in cache_
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// draw according to cached metrics
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathMacro.C b/src/mathed/InsetMathMacro.C
index bb0966d8b6..5126e19ccc 100644
--- a/src/mathed/InsetMathMacro.C
+++ b/src/mathed/InsetMathMacro.C
@@ -59,7 +59,7 @@ void MathMacro::cursorPos(BufferView const & bv,
 }
 
 
-void MathMacro::metrics(MetricsInfo & mi, Dimension & dim) const
+bool MathMacro::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (!MacroTable::globalMacros().has(name())) {
 		mathed_string_dim(mi.base.font, "Unknown: " + name(), dim);
@@ -84,7 +84,10 @@ void MathMacro::metrics(MetricsInfo & mi, Dimension & dim) const
 		expanded_.metrics(mi, dim);
 	}
 	metricsMarkers2(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathMacro.h b/src/mathed/InsetMathMacro.h
index 24cd74586c..8a6a6997c7 100644
--- a/src/mathed/InsetMathMacro.h
+++ b/src/mathed/InsetMathMacro.h
@@ -34,7 +34,7 @@ public:
 	/// draw selection background
 	void drawSelection(PainterInfo & pi, int x, int y) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// get cursor position
 	void cursorPos(BufferView const & bv, CursorSlice const & sl,
 		bool boundary, int & x, int & y) const;
diff --git a/src/mathed/InsetMathMakebox.C b/src/mathed/InsetMathMakebox.C
index 068d42327a..2ef56d955a 100644
--- a/src/mathed/InsetMathMakebox.C
+++ b/src/mathed/InsetMathMakebox.C
@@ -34,7 +34,7 @@ auto_ptr<InsetBase> InsetMathMakebox::doClone() const
 }
 
 
-void InsetMathMakebox::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathMakebox::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, from_ascii("textnormal"));
 	w_ = mathed_char_width(mi.base.font, '[');
@@ -44,7 +44,10 @@ void InsetMathMakebox::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim  += cell(2).dim();
 	dim.wid += 4 * w_ + 4;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathMakebox.h b/src/mathed/InsetMathMakebox.h
index 859701154f..1c459f2ea1 100644
--- a/src/mathed/InsetMathMakebox.h
+++ b/src/mathed/InsetMathMakebox.h
@@ -25,7 +25,7 @@ public:
 	///
 	InsetMathMakebox();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathNumber.C b/src/mathed/InsetMathNumber.C
index 9ab909cf08..41e7c60a7c 100644
--- a/src/mathed/InsetMathNumber.C
+++ b/src/mathed/InsetMathNumber.C
@@ -33,9 +33,13 @@ auto_ptr<InsetBase> InsetMathNumber::doClone() const
 }
 
 
-void InsetMathNumber::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathNumber::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	mathed_string_dim(mi.base.font, str_, dim);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathNumber.h b/src/mathed/InsetMathNumber.h
index d6ccbb0d20..606603e6df 100644
--- a/src/mathed/InsetMathNumber.h
+++ b/src/mathed/InsetMathNumber.h
@@ -26,7 +26,7 @@ public:
 	///
 	explicit InsetMathNumber(docstring const & s);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathOverset.C b/src/mathed/InsetMathOverset.C
index dfca03bd5e..0ecc01577f 100644
--- a/src/mathed/InsetMathOverset.C
+++ b/src/mathed/InsetMathOverset.C
@@ -30,7 +30,7 @@ auto_ptr<InsetBase> InsetMathOverset::doClone() const
 }
 
 
-void InsetMathOverset::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathOverset::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(1).metrics(mi);
 	FracChanger dummy(mi.base);
@@ -39,7 +39,10 @@ void InsetMathOverset::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = cell(1).ascent() + cell(0).height() + 4;
 	dim.des = cell(1).descent();
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathOverset.h b/src/mathed/InsetMathOverset.h
index cff7e7a229..c74557c04c 100644
--- a/src/mathed/InsetMathOverset.h
+++ b/src/mathed/InsetMathOverset.h
@@ -22,7 +22,7 @@ namespace lyx {
 class InsetMathOverset : public InsetMathFracBase {
 public:
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathPar.C b/src/mathed/InsetMathPar.C
index 3f8be93d00..6ebe584c92 100644
--- a/src/mathed/InsetMathPar.C
+++ b/src/mathed/InsetMathPar.C
@@ -28,11 +28,15 @@ InsetMathPar::InsetMathPar(MathArray const & ar)
 }
 
 
-void InsetMathPar::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathPar::metrics(MetricsInfo & mi, Dimension & dim) const
 {
+	dim = dim_;
 	FontSetChanger dummy1(mi.base, "textnormal");
 	InsetMathGrid::metrics(mi);
+	if (dim_ == dim)
+		return false;
 	dim = dim_;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathPar.h b/src/mathed/InsetMathPar.h
index 6fd28850fd..3f980e2fec 100644
--- a/src/mathed/InsetMathPar.h
+++ b/src/mathed/InsetMathPar.h
@@ -27,7 +27,7 @@ public:
 	///
 	mode_type currentMode() const { return TEXT_MODE; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathPhantom.C b/src/mathed/InsetMathPhantom.C
index 75fd7774cd..97f0bf2fd8 100644
--- a/src/mathed/InsetMathPhantom.C
+++ b/src/mathed/InsetMathPhantom.C
@@ -35,11 +35,14 @@ std::auto_ptr<InsetBase> InsetMathPhantom::doClone() const
 }
 
 
-void InsetMathPhantom::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathPhantom::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathPhantom.h b/src/mathed/InsetMathPhantom.h
index dfb7b60f7c..edefb74dff 100644
--- a/src/mathed/InsetMathPhantom.h
+++ b/src/mathed/InsetMathPhantom.h
@@ -28,7 +28,7 @@ public:
 	///
 	explicit InsetMathPhantom(Kind);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathRoot.C b/src/mathed/InsetMathRoot.C
index 11a9221505..bf0112a2da 100644
--- a/src/mathed/InsetMathRoot.C
+++ b/src/mathed/InsetMathRoot.C
@@ -38,14 +38,17 @@ auto_ptr<InsetBase> InsetMathRoot::doClone() const
 }
 
 
-void InsetMathRoot::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathRoot::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	InsetMathNest::metrics(mi);
 	dim.asc = max(cell(0).ascent()  + 5, cell(1).ascent())  + 2;
 	dim.des = max(cell(1).descent() + 5, cell(0).descent()) + 2;
 	dim.wid = cell(0).width() + cell(1).width() + 10;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathRoot.h b/src/mathed/InsetMathRoot.h
index ac69d1d933..57af6ae83a 100644
--- a/src/mathed/InsetMathRoot.h
+++ b/src/mathed/InsetMathRoot.h
@@ -27,7 +27,7 @@ public:
 	///
 	bool idxUpDown(LCursor & cur, bool up) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMathScript.C b/src/mathed/InsetMathScript.C
index c47e239892..b6b3d87e4a 100644
--- a/src/mathed/InsetMathScript.C
+++ b/src/mathed/InsetMathScript.C
@@ -213,7 +213,7 @@ int InsetMathScript::ndes() const
 }
 
 
-void InsetMathScript::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathScript::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	ScriptChanger dummy(mi.base);
@@ -238,7 +238,10 @@ void InsetMathScript::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = dy1() + (hasUp() ? up().ascent() : 0);
 	dim.des = dy0() + (hasDown() ? down().descent() : 0);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathScript.h b/src/mathed/InsetMathScript.h
index adffa97ff7..2c00668384 100644
--- a/src/mathed/InsetMathScript.h
+++ b/src/mathed/InsetMathScript.h
@@ -33,7 +33,7 @@ public:
 	///
 	mode_type currentMode() const { return MATH_MODE; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathSize.C b/src/mathed/InsetMathSize.C
index 562aa0cd65..86ec8d8a25 100644
--- a/src/mathed/InsetMathSize.C
+++ b/src/mathed/InsetMathSize.C
@@ -36,12 +36,15 @@ auto_ptr<InsetBase> InsetMathSize::doClone() const
 }
 
 
-void InsetMathSize::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathSize::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	StyleChanger dummy(mi.base, style_);
 	cell(0).metrics(mi, dim);
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathSize.h b/src/mathed/InsetMathSize.h
index 5a9767af03..f749e3ef5c 100644
--- a/src/mathed/InsetMathSize.h
+++ b/src/mathed/InsetMathSize.h
@@ -29,7 +29,7 @@ public:
 	/// we write extra braces in any case...
 	bool extraBraces() const { return true; }
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 
diff --git a/src/mathed/InsetMathSpace.C b/src/mathed/InsetMathSpace.C
index fd0f56997f..0c44fabf5b 100644
--- a/src/mathed/InsetMathSpace.C
+++ b/src/mathed/InsetMathSpace.C
@@ -85,11 +85,15 @@ int InsetMathSpace::descent() const
 }
 
 
-void InsetMathSpace::metrics(MetricsInfo &, Dimension & dim) const
+bool InsetMathSpace::metrics(MetricsInfo &, Dimension & dim) const
 {
 	dim.wid = width();
 	dim.asc = ascent();
 	dim.des = descent();
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathSpace.h b/src/mathed/InsetMathSpace.h
index a3e06d634e..1a41373436 100644
--- a/src/mathed/InsetMathSpace.h
+++ b/src/mathed/InsetMathSpace.h
@@ -38,7 +38,7 @@ public:
 	///
 	int width() const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMathSqrt.C b/src/mathed/InsetMathSqrt.C
index 82edc46126..33b5e77514 100644
--- a/src/mathed/InsetMathSqrt.C
+++ b/src/mathed/InsetMathSqrt.C
@@ -34,14 +34,17 @@ auto_ptr<InsetBase> InsetMathSqrt::doClone() const
 }
 
 
-void InsetMathSqrt::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathSqrt::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi, dim);
 	dim.asc += 4;
 	dim.des += 2;
 	dim.wid += 12;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathSqrt.h b/src/mathed/InsetMathSqrt.h
index 8e19b367d8..a4407d4a28 100644
--- a/src/mathed/InsetMathSqrt.h
+++ b/src/mathed/InsetMathSqrt.h
@@ -27,7 +27,7 @@ public:
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void drawT(TextPainter &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathStackrel.C b/src/mathed/InsetMathStackrel.C
index 197d78df60..b4e245faa3 100644
--- a/src/mathed/InsetMathStackrel.C
+++ b/src/mathed/InsetMathStackrel.C
@@ -32,7 +32,7 @@ auto_ptr<InsetBase> InsetMathStackrel::doClone() const
 }
 
 
-void InsetMathStackrel::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathStackrel::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(1).metrics(mi);
 	FracChanger dummy(mi.base);
@@ -41,7 +41,10 @@ void InsetMathStackrel::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = cell(1).ascent() + cell(0).height() + 4;
 	dim.des = cell(1).descent();
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathStackrel.h b/src/mathed/InsetMathStackrel.h
index 5799df2749..75c07f7f62 100644
--- a/src/mathed/InsetMathStackrel.h
+++ b/src/mathed/InsetMathStackrel.h
@@ -28,7 +28,7 @@ public:
 	///
 	InsetMathStackrel();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 
diff --git a/src/mathed/InsetMathString.C b/src/mathed/InsetMathString.C
index 78637265d7..dc9e5b8858 100644
--- a/src/mathed/InsetMathString.C
+++ b/src/mathed/InsetMathString.C
@@ -33,9 +33,13 @@ auto_ptr<InsetBase> InsetMathString::doClone() const
 }
 
 
-void InsetMathString::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathString::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	mathed_string_dim(mi.base.font, str_, dim);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathString.h b/src/mathed/InsetMathString.h
index f0803a8e2b..495de2f005 100644
--- a/src/mathed/InsetMathString.h
+++ b/src/mathed/InsetMathString.h
@@ -26,7 +26,7 @@ public:
 	///
 	explicit InsetMathString(docstring const & s);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathSubstack.C b/src/mathed/InsetMathSubstack.C
index c89bbc143d..8b7fd3d571 100644
--- a/src/mathed/InsetMathSubstack.C
+++ b/src/mathed/InsetMathSubstack.C
@@ -42,7 +42,7 @@ auto_ptr<InsetBase> InsetMathSubstack::doClone() const
 }
 
 
-void InsetMathSubstack::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathSubstack::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (mi.base.style == LM_ST_DISPLAY) {
 		StyleChanger dummy(mi.base, LM_ST_TEXT);
@@ -50,7 +50,10 @@ void InsetMathSubstack::metrics(MetricsInfo & mi, Dimension & dim) const
 	} else {
 		InsetMathGrid::metrics(mi, dim);
 	}
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathSubstack.h b/src/mathed/InsetMathSubstack.h
index c184dc4a97..417adc1d9f 100644
--- a/src/mathed/InsetMathSubstack.h
+++ b/src/mathed/InsetMathSubstack.h
@@ -25,7 +25,7 @@ public:
 	///
 	InsetMathSubstack();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathSymbol.C b/src/mathed/InsetMathSymbol.C
index 206b6304db..1a5176b666 100644
--- a/src/mathed/InsetMathSymbol.C
+++ b/src/mathed/InsetMathSymbol.C
@@ -54,7 +54,7 @@ docstring InsetMathSymbol::name() const
 }
 
 
-void InsetMathSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	//lyxerr << "metrics: symbol: '" << sym_->name
 	//	<< "' in font: '" << sym_->inset
@@ -84,6 +84,10 @@ void InsetMathSymbol::metrics(MetricsInfo & mi, Dimension & dim) const
 			scriptable_ = true;
 
 	width_ = dim.wid;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathSymbol.h b/src/mathed/InsetMathSymbol.h
index 1231983ae7..c34d30c696 100644
--- a/src/mathed/InsetMathSymbol.h
+++ b/src/mathed/InsetMathSymbol.h
@@ -32,7 +32,7 @@ public:
 	///
 	explicit InsetMathSymbol(docstring const & name);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathTFrac.C b/src/mathed/InsetMathTFrac.C
index 102c061e2c..f361dc7872 100644
--- a/src/mathed/InsetMathTFrac.C
+++ b/src/mathed/InsetMathTFrac.C
@@ -40,15 +40,18 @@ auto_ptr<InsetBase> InsetMathTFrac::doClone() const
 }
 
 
-void InsetMathTFrac::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathTFrac::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	StyleChanger dummy(mi.base, LM_ST_SCRIPT);
 	cell(0).metrics(mi);
 	cell(1).metrics(mi);
-	dim_.wid = max(cell(0).width(), cell(1).width()) + 2;
-	dim_.asc = cell(0).height() + 2 + 5;
-	dim_.des = cell(1).height() + 2 - 5;
-	dim = dim_;
+	dim.wid = max(cell(0).width(), cell(1).width()) + 2;
+	dim.asc = cell(0).height() + 2 + 5;
+	dim.des = cell(1).height() + 2 - 5;
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathTFrac.h b/src/mathed/InsetMathTFrac.h
index 045a3e35fb..ee8f4c9524 100644
--- a/src/mathed/InsetMathTFrac.h
+++ b/src/mathed/InsetMathTFrac.h
@@ -24,7 +24,7 @@ public:
 	///
 	InsetMathTFrac();
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathTabular.C b/src/mathed/InsetMathTabular.C
index 663559d79b..54ef64cbbe 100644
--- a/src/mathed/InsetMathTabular.C
+++ b/src/mathed/InsetMathTabular.C
@@ -51,12 +51,15 @@ auto_ptr<InsetBase> InsetMathTabular::doClone() const
 }
 
 
-void InsetMathTabular::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathTabular::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	FontSetChanger dummy(mi.base, "textnormal");
 	InsetMathGrid::metrics(mi, dim);
 	dim.wid += 6;
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathTabular.h b/src/mathed/InsetMathTabular.h
index 13b4960e50..4e86b44ab9 100644
--- a/src/mathed/InsetMathTabular.h
+++ b/src/mathed/InsetMathTabular.h
@@ -29,7 +29,7 @@ public:
 	///
 	InsetMathTabular(docstring const &, char valign, docstring const & halign);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathUnderset.C b/src/mathed/InsetMathUnderset.C
index 6218b6e72c..f756a49f13 100644
--- a/src/mathed/InsetMathUnderset.C
+++ b/src/mathed/InsetMathUnderset.C
@@ -31,7 +31,7 @@ auto_ptr<InsetBase> InsetMathUnderset::doClone() const
 }
 
 
-void InsetMathUnderset::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathUnderset::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(1).metrics(mi);
 	FracChanger dummy(mi.base);
@@ -40,7 +40,10 @@ void InsetMathUnderset::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = cell(1).ascent();
 	dim.des = cell(1).descent() + cell(0).height() + 4;
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathUnderset.h b/src/mathed/InsetMathUnderset.h
index a53e74266a..4eb2fce517 100644
--- a/src/mathed/InsetMathUnderset.h
+++ b/src/mathed/InsetMathUnderset.h
@@ -22,7 +22,7 @@ namespace lyx {
 class InsetMathUnderset : public InsetMathFracBase {
 public:
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathUnknown.C b/src/mathed/InsetMathUnknown.C
index 007989b2bc..302c913829 100644
--- a/src/mathed/InsetMathUnknown.C
+++ b/src/mathed/InsetMathUnknown.C
@@ -53,10 +53,13 @@ void InsetMathUnknown::normalize(NormalStream & os) const
 }
 
 
-void InsetMathUnknown::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathUnknown::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	mathed_string_dim(mi.base.font, name_, dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathUnknown.h b/src/mathed/InsetMathUnknown.h
index 7872e73b36..d1ab2bc50a 100644
--- a/src/mathed/InsetMathUnknown.h
+++ b/src/mathed/InsetMathUnknown.h
@@ -25,7 +25,7 @@ public:
 	explicit InsetMathUnknown(docstring const & name,
 		bool final = true, bool black = false);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathXArrow.C b/src/mathed/InsetMathXArrow.C
index a6ff4e626a..b8f1f3af98 100644
--- a/src/mathed/InsetMathXArrow.C
+++ b/src/mathed/InsetMathXArrow.C
@@ -36,7 +36,7 @@ auto_ptr<InsetBase> InsetMathXArrow::doClone() const
 }
 
 
-void InsetMathXArrow::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathXArrow::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	ScriptChanger dummy(mi.base);
 	cell(0).metrics(mi);
@@ -45,7 +45,10 @@ void InsetMathXArrow::metrics(MetricsInfo & mi, Dimension & dim) const
 	dim.asc = cell(0).height() + 10;
 	dim.des = cell(1).height();
 	metricsMarkers(dim);
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathXArrow.h b/src/mathed/InsetMathXArrow.h
index 05bc2740bb..0355b15fd0 100644
--- a/src/mathed/InsetMathXArrow.h
+++ b/src/mathed/InsetMathXArrow.h
@@ -28,7 +28,7 @@ public:
 	///
 	void write(WriteStream & os) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void normalize(NormalStream & os) const;
 	///
diff --git a/src/mathed/InsetMathXYArrow.C b/src/mathed/InsetMathXYArrow.C
index 890d7cc792..1b97ff5407 100644
--- a/src/mathed/InsetMathXYArrow.C
+++ b/src/mathed/InsetMathXYArrow.C
@@ -81,7 +81,7 @@ MathArray const & InsetMathXYArrow::sourceCell() const
 }
 
 
-void InsetMathXYArrow::metrics(MetricsInfo & mi) const
+bool InsetMathXYArrow::metrics(MetricsInfo & mi) const
 {
 	InsetMathNest::metrics(mi);
 	mi_   = mi;
diff --git a/src/mathed/InsetMathXYArrow.h b/src/mathed/InsetMathXYArrow.h
index 42552c48eb..334b8f58cb 100644
--- a/src/mathed/InsetMathXYArrow.h
+++ b/src/mathed/InsetMathXYArrow.h
@@ -30,7 +30,7 @@ public:
 	///
 	virtual std::auto_ptr<InsetBase> clone() const;
 	///
-	void metrics(MetricsInfo & mi) const;
+	bool metrics(MetricsInfo & mi) const;
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
diff --git a/src/mathed/InsetMathXYMatrix.C b/src/mathed/InsetMathXYMatrix.C
index 679f271289..cbeba96583 100644
--- a/src/mathed/InsetMathXYMatrix.C
+++ b/src/mathed/InsetMathXYMatrix.C
@@ -43,11 +43,15 @@ int InsetMathXYMatrix::rowsep() const
 }
 
 
-void InsetMathXYMatrix::metrics(MetricsInfo & mi, Dimension & dim) const
+bool InsetMathXYMatrix::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	if (mi.base.style == LM_ST_DISPLAY)
 		mi.base.style = LM_ST_TEXT;
 	InsetMathGrid::metrics(mi, dim);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/InsetMathXYMatrix.h b/src/mathed/InsetMathXYMatrix.h
index 8cef0b8656..949f488f94 100644
--- a/src/mathed/InsetMathXYMatrix.h
+++ b/src/mathed/InsetMathXYMatrix.h
@@ -24,7 +24,7 @@ public:
 	///
 	InsetMathXYMatrix(LyXLength const & = LyXLength(), char c = '\0');
 	///
-	void metrics(MetricsInfo &, Dimension &) const;
+	bool metrics(MetricsInfo &, Dimension &) const;
 	///
 	InsetMathXYMatrix const * asXYMatrixInset() const { return this; }
 	///
diff --git a/src/mathed/MathData.C b/src/mathed/MathData.C
index 731a7753d2..f36bf570ba 100644
--- a/src/mathed/MathData.C
+++ b/src/mathed/MathData.C
@@ -211,10 +211,14 @@ void MathArray::touch() const
 }
 
 
-void MathArray::metrics(MetricsInfo & mi, Dimension & dim) const
+bool MathArray::metrics(MetricsInfo & mi, Dimension & dim) const
 {
-	metrics(mi);
 	dim = dim_;
+	metrics(mi);
+	if (dim_ == dim)
+		return false;
+	dim = dim_;
+	return true;
 }
 
 
diff --git a/src/mathed/MathData.h b/src/mathed/MathData.h
index 678e9976d5..bf4d5909c0 100644
--- a/src/mathed/MathData.h
+++ b/src/mathed/MathData.h
@@ -106,7 +106,7 @@ public:
 	/// rebuild cached metrics information
 	void metrics(MetricsInfo & mi) const;
 	/// rebuild cached metrics information
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// redraw cell using cache metrics information
 	void draw(PainterInfo & pi, int x, int y) const;
 	/// rebuild cached metrics information
@@ -151,12 +151,13 @@ public:
 	/// dimensions of cell
 	void setDim(Dimension const & d) const { dim_ = d; }
 
+protected:
+	/// cached dimensions of cell
+	mutable Dimension dim_;
+
 private:
 	/// is this an exact match at this position?
 	bool find1(MathArray const & ar, size_type pos) const;
-
-	/// cached dimensions of cell
-	mutable Dimension dim_;
 };
 
 ///
diff --git a/src/mathed/MathMacroArgument.C b/src/mathed/MathMacroArgument.C
index 999079b640..14468dd56b 100644
--- a/src/mathed/MathMacroArgument.C
+++ b/src/mathed/MathMacroArgument.C
@@ -55,10 +55,13 @@ void MathMacroArgument::write(WriteStream & os) const
 }
 
 
-void MathMacroArgument::metrics(MetricsInfo & mi, Dimension & dim) const
+bool MathMacroArgument::metrics(MetricsInfo & mi, Dimension & dim) const
 {
-	mathed_string_dim(mi.base.font, str_, dim_);
-	dim = dim_;
+	mathed_string_dim(mi.base.font, str_, dim);
+	if (dim_ == dim)
+		return false;
+	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/MathMacroArgument.h b/src/mathed/MathMacroArgument.h
index 32729a6df7..1fe0f2ea9f 100644
--- a/src/mathed/MathMacroArgument.h
+++ b/src/mathed/MathMacroArgument.h
@@ -25,7 +25,7 @@ public:
 	///
 	explicit MathMacroArgument(std::size_t);
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	///
 	void draw(PainterInfo &, int x, int y) const;
 	///
diff --git a/src/mathed/MathMacroTemplate.C b/src/mathed/MathMacroTemplate.C
index 1cf6c25e11..aedca14612 100644
--- a/src/mathed/MathMacroTemplate.C
+++ b/src/mathed/MathMacroTemplate.C
@@ -112,7 +112,7 @@ docstring MathMacroTemplate::prefix() const
 }
 
 
-void MathMacroTemplate::metrics(MetricsInfo & mi, Dimension & dim) const
+bool MathMacroTemplate::metrics(MetricsInfo & mi, Dimension & dim) const
 {
 	cell(0).metrics(mi);
 	cell(1).metrics(mi);
@@ -121,7 +121,10 @@ void MathMacroTemplate::metrics(MetricsInfo & mi, Dimension & dim) const
 		+ theFontMetrics(mi.base.font).width(dp);
 	dim.asc = std::max(cell(0).ascent(),  cell(1).ascent())  + 7;
 	dim.des = std::max(cell(0).descent(), cell(1).descent()) + 7;
+	if (dim_ == dim)
+		return false;
 	dim_ = dim;
+	return true;
 }
 
 
diff --git a/src/mathed/MathMacroTemplate.h b/src/mathed/MathMacroTemplate.h
index c319ae5a8e..4682df22e8 100644
--- a/src/mathed/MathMacroTemplate.h
+++ b/src/mathed/MathMacroTemplate.h
@@ -55,7 +55,7 @@ public:
 	///
 	void draw(PainterInfo & pi, int x, int y) const;
 	///
-	void metrics(MetricsInfo & mi, Dimension & dim) const;
+	bool metrics(MetricsInfo & mi, Dimension & dim) const;
 	/// identifies macro templates
 	MathMacroTemplate * asMacroTemplate() { return this; }
 	/// identifies macro templates
diff --git a/src/text.C b/src/text.C
index e23eba2e88..a0a3c05f83 100644
--- a/src/text.C
+++ b/src/text.C
@@ -1833,6 +1833,8 @@ bool LyXText::redoParagraph(BufferView & bv, pit_type const pit)
 	Paragraph & par = pars_[pit];
 	Buffer const & buffer = *bv.buffer();
 
+	bool changed = false;
+
 	// Add bibitem insets if necessary
 	if (par.layout()->labeltype == LABEL_BIBLIO) {
 		bool hasbibitem(false);
@@ -1871,7 +1873,7 @@ bool LyXText::redoParagraph(BufferView & bv, pit_type const pit)
 			bufferfont :
 			getFont(buffer, par, ii->pos);
 		MetricsInfo mi(&bv, font, w);
-		ii->inset->metrics(mi, dim);
+		changed |= ii->inset->metrics(mi, dim);
 	}
 
 	// rebreak the paragraph
@@ -1908,16 +1910,16 @@ bool LyXText::redoParagraph(BufferView & bv, pit_type const pit)
 	dim.asc += par.rows()[0].ascent();
 	dim.des -= par.rows()[0].ascent();
 
-	bool const same = dim.height() == par.dim().height();
+	changed |= dim.height() != par.dim().height();
 
 	par.dim() = dim;
 	//lyxerr << "redoParagraph: " << par.rows().size() << " rows\n";
 
-	return !same;
+	return changed;
 }
 
 
-void LyXText::metrics(MetricsInfo & mi, Dimension & dim)
+bool LyXText::metrics(MetricsInfo & mi, Dimension & dim)
 {
 	//BOOST_ASSERT(mi.base.textwidth);
 	if (mi.base.textwidth)
@@ -1927,10 +1929,12 @@ void LyXText::metrics(MetricsInfo & mi, Dimension & dim)
 	// save the caller's font locally:
 	font_ = mi.base.font;
 
+	bool changed = false;
+
 	unsigned int h = 0;
 	unsigned int w = 0;
 	for (pit_type pit = 0, n = paragraphs().size(); pit != n; ++pit) {
-		redoParagraph(*mi.base.bv, pit);
+		changed |= redoParagraph(*mi.base.bv, pit);
 		Paragraph & par = paragraphs()[pit];
 		h += par.height();
 		if (w < par.width())
@@ -1941,7 +1945,9 @@ void LyXText::metrics(MetricsInfo & mi, Dimension & dim)
 	dim.asc = pars_[0].ascent();
 	dim.des = h - dim.asc;
 
+	changed |= dim_ != dim;
 	dim_ = dim;
+	return changed;
 }