diff --git a/src/insets/insetbase.h b/src/insets/insetbase.h
index eef82e0259..55524e17c7 100644
--- a/src/insets/insetbase.h
+++ b/src/insets/insetbase.h
@@ -402,6 +402,8 @@ public:
 	virtual void setChange(Change const &) {}
 	/// accept the changes within the inset
 	virtual void acceptChanges() {};
+	/// reject the changes within the inset
+	virtual void rejectChanges() {};
 
 	/// pretty arbitrary
 	virtual int width() const { return 10; }
diff --git a/src/insets/insettabular.C b/src/insets/insettabular.C
index c6f82d3a4c..18ad857530 100644
--- a/src/insets/insettabular.C
+++ b/src/insets/insettabular.C
@@ -1921,6 +1921,13 @@ void InsetTabular::acceptChanges()
 }
 
 
+void InsetTabular::rejectChanges()
+{
+	for (idx_type idx = 0; idx < nargs(); ++idx)
+		cell(idx)->rejectChanges();
+}
+
+
 bool InsetTabular::forceDefaultParagraphs(idx_type cell) const
 {
 	return tabular.getPWidth(cell).zero();
diff --git a/src/insets/insettabular.h b/src/insets/insettabular.h
index 469e3d27e4..a43e22e0bd 100644
--- a/src/insets/insettabular.h
+++ b/src/insets/insettabular.h
@@ -119,6 +119,8 @@ public:
 	void setChange(Change const & change);
 	/// accept the changes within the inset
 	void acceptChanges();
+	/// reject the changes within the inset
+	void rejectChanges();
 
 	// this should return true if we have a "normal" cell, otherwise false.
 	// "normal" means without width set!
diff --git a/src/insets/insettext.C b/src/insets/insettext.C
index 39fe2606a0..96c7dcdf8e 100644
--- a/src/insets/insettext.C
+++ b/src/insets/insettext.C
@@ -284,6 +284,18 @@ void InsetText::acceptChanges()
 }
 
 
+void InsetText::rejectChanges()
+{
+	ParagraphList::iterator pit = paragraphs().begin();
+	ParagraphList::iterator end = paragraphs().end();
+	for (; pit != end; ++pit) {
+		// FIXME: change tracking (MG)
+		// we must handle end-of-par chars!
+		pit->rejectChanges(0, pit->size() + 1);
+	}
+}
+
+
 int InsetText::latex(Buffer const & buf, odocstream & os,
 		     OutputParams const & runparams) const
 {
diff --git a/src/insets/insettext.h b/src/insets/insettext.h
index 34219d0bf6..0b33eb23eb 100644
--- a/src/insets/insettext.h
+++ b/src/insets/insettext.h
@@ -106,6 +106,8 @@ public:
 	void setChange(Change const & change);
 	/// accept the changes within the inset
 	void acceptChanges();
+	/// reject the changes within the inset
+	void rejectChanges();
 
 	/// append text onto the existing text
 	void appendParagraphs(Buffer * bp, ParagraphList &);
diff --git a/src/paragraph.C b/src/paragraph.C
index 6f9701139c..4c9cf29828 100644
--- a/src/paragraph.C
+++ b/src/paragraph.C
@@ -1447,9 +1447,9 @@ void Paragraph::acceptChanges(pos_type start, pos_type end)
 }
 
 
-void Paragraph::rejectChange(pos_type start, pos_type end)
+void Paragraph::rejectChanges(pos_type start, pos_type end)
 {
-	return pimpl_->rejectChange(start, end);
+	return pimpl_->rejectChanges(start, end);
 }
 
 
diff --git a/src/paragraph.h b/src/paragraph.h
index 60dd0fba93..77635bf2a3 100644
--- a/src/paragraph.h
+++ b/src/paragraph.h
@@ -220,8 +220,8 @@ public:
 	/// accept changes within the given range
 	void acceptChanges(pos_type start, pos_type end);
 
-	/// reject change
-	void rejectChange(pos_type start, pos_type end);
+	/// reject changes within the given range
+	void rejectChanges(pos_type start, pos_type end);
 
 	/// Paragraphs can contain "manual labels", for example, Description
 	/// environment. The text for this user-editable label is stored in
diff --git a/src/paragraph_pimpl.C b/src/paragraph_pimpl.C
index 1d9512a328..df802cec42 100644
--- a/src/paragraph_pimpl.C
+++ b/src/paragraph_pimpl.C
@@ -89,6 +89,9 @@ void Paragraph::Pimpl::setContentsFromPar(Paragraph const & par)
 
 bool Paragraph::Pimpl::isChanged(pos_type start, pos_type end) const
 {
+	BOOST_ASSERT(start >= 0 && start <= size());
+	BOOST_ASSERT(end > start && end <= size() + 1);
+
 	return changes_.isChanged(start, end);
 }
 
@@ -111,6 +114,8 @@ void Paragraph::Pimpl::setChange(Change const & change)
 
 void Paragraph::Pimpl::setChange(pos_type pos, Change const & change)
 {
+	BOOST_ASSERT(pos >= 0 && pos <= size());
+
 	changes_.set(change, pos);
 
 	// FIXME: change tracking (MG)
@@ -123,12 +128,17 @@ void Paragraph::Pimpl::setChange(pos_type pos, Change const & change)
 
 Change const Paragraph::Pimpl::lookupChange(pos_type pos) const
 {
+	BOOST_ASSERT(pos >= 0 && pos <= size());
+
 	return changes_.lookup(pos);
 }
 
 
 void Paragraph::Pimpl::acceptChanges(pos_type start, pos_type end)
 {
+	BOOST_ASSERT(start >= 0 && start <= size());
+	BOOST_ASSERT(end > start && end <= size() + 1);
+	
 	for (pos_type pos = start; pos < end; ++pos) {
 		switch (lookupChange(pos).type) {
 			case Change::UNCHANGED:
@@ -139,8 +149,8 @@ void Paragraph::Pimpl::acceptChanges(pos_type start, pos_type end)
 				break;
 
 			case Change::DELETED:
-				// Suppress access to nonexistent
-				// "end-of-paragraph char":
+				// Suppress access to non-existent
+				// "end-of-paragraph char"
 				if (pos < size()) {
 					eraseChar(pos, false);
 					--end;
@@ -157,52 +167,50 @@ void Paragraph::Pimpl::acceptChanges(pos_type start, pos_type end)
 }
 
 
-void Paragraph::Pimpl::rejectChange(pos_type start, pos_type end)
+void Paragraph::Pimpl::rejectChanges(pos_type start, pos_type end)
 {
-	// FIXME: change tracking (MG)
-	return;
+	BOOST_ASSERT(start >= 0 && start <= size());
+	BOOST_ASSERT(end > start && end <= size() + 1);
 
-	// care for empty pars
-
-	pos_type i = start;
-
-	for (; i < end; ++i) {
-		switch (lookupChange(i).type) {
+	for (pos_type pos = start; pos < end; ++pos) {
+		switch (lookupChange(pos).type) {
 			case Change::UNCHANGED:
 				break;
 
 			case Change::INSERTED:
-				if (i < size()) {
-					eraseChar(i, false);
+				// Suppress access to non-existent
+				// "end-of-paragraph char"
+				if (pos < size()) {
+					eraseChar(pos, false);
 					--end;
-					--i;
+					--pos;
 				}
 				break;
 
 			case Change::DELETED:
-				// FIXME: change tracking (MG)
-				changes_.set(Change(Change::UNCHANGED), i);
-				// No real char at position size():
-				if (i < size() && owner_->isInset(i))
-					// FIXME: change tracking (MG)
-					owner_->getInset(i)->setChange(Change(Change::UNCHANGED));
+				changes_.set(Change(Change::UNCHANGED), pos);
 				break;
 		}
+
+		// also reject changes in nested insets
+		if (pos < size() && owner_->isInset(pos)) {
+			owner_->getInset(pos)->rejectChanges();
+		}
 	}
-	// FIXME: change tracking (MG)
-	// changes_.reset(Change::UNCHANGED);
 }
 
 
 Paragraph::value_type Paragraph::Pimpl::getChar(pos_type pos) const
 {
+	BOOST_ASSERT(pos >= 0 && pos <= size());
+
 	return owner_->getChar(pos);
 }
 
 
 void Paragraph::Pimpl::insertChar(pos_type pos, value_type c, Change const & change)
 {
-	BOOST_ASSERT(pos <= size());
+	BOOST_ASSERT(pos >= 0 && pos <= size());
 
 	// track change
 	changes_.insert(change, pos);
@@ -235,7 +243,7 @@ void Paragraph::Pimpl::insertInset(pos_type pos, InsetBase * inset,
                                    Change const & change)
 {
 	BOOST_ASSERT(inset);
-	BOOST_ASSERT(pos <= size());
+	BOOST_ASSERT(pos >= 0 && pos <= size());
 
 	insertChar(pos, META_INSET, change);
 	BOOST_ASSERT(owner_->text_[pos] == META_INSET);
@@ -247,7 +255,7 @@ void Paragraph::Pimpl::insertInset(pos_type pos, InsetBase * inset,
 
 bool Paragraph::Pimpl::eraseChar(pos_type pos, bool trackChanges)
 {
-	BOOST_ASSERT(pos <= size());
+	BOOST_ASSERT(pos >= 0 && pos <= size());
 
 	if (trackChanges) {
 		Change::Type changetype(changes_.lookup(pos).type);
@@ -317,6 +325,9 @@ bool Paragraph::Pimpl::eraseChar(pos_type pos, bool trackChanges)
 
 int Paragraph::Pimpl::eraseChars(pos_type start, pos_type end, bool trackChanges)
 {
+	BOOST_ASSERT(start >= 0 && start <= size());
+	BOOST_ASSERT(end > start && end <= size() + 1);
+
 	pos_type i = start;
 	for (pos_type count = end - start; count; --count) {
 		if (!eraseChar(i, trackChanges))
diff --git a/src/paragraph_pimpl.h b/src/paragraph_pimpl.h
index facbcb22fc..221fb94143 100644
--- a/src/paragraph_pimpl.h
+++ b/src/paragraph_pimpl.h
@@ -51,8 +51,8 @@ public:
 	void setChange(pos_type pos, Change const & change);
 	/// accept changes within the given range
 	void acceptChanges(pos_type start, pos_type end);
-	/// reject change
-	void rejectChange(pos_type start, pos_type end);
+	/// reject changes within the given range
+	void rejectChanges(pos_type start, pos_type end);
 
 	///
 	value_type getChar(pos_type pos) const;
diff --git a/src/text.C b/src/text.C
index d953f955d3..8ab02dfa35 100644
--- a/src/text.C
+++ b/src/text.C
@@ -1501,7 +1501,7 @@ void LyXText::rejectChange(LCursor & cur)
 		pos_type left  = ( pit == it.pit() ? it.pos() : 0 );
 		pos_type right =
 		    ( pit == et.pit() ? et.pos() : pars_[pit].size() + 1 );
-		pars_[pit].rejectChange(left, right);
+		pars_[pit].rejectChanges(left, right);
 	}
 	if (isInserted) {
 		ParagraphList & plist = paragraphs();