diff --git a/src/coordcache.C b/src/coordcache.C
index 6f75791eb9..11e5a8db3e 100644
--- a/src/coordcache.C
+++ b/src/coordcache.C
@@ -14,10 +14,10 @@ void lyxbreaker(void const * data, const char * hint, int size)
 
 void CoordCache::clear()
 {
-	lyxerr << "CoordCache: removing " << arrays_.data_.size()
-		<< " arrays" << std::endl;
-	lyxerr << "CoordCache: removing " << insets_.data_.size()
-		<< " insets" << std::endl;
+//	lyxerr << "CoordCache: removing " << arrays_.data_.size()
+//		<< " arrays" << std::endl;
+//	lyxerr << "CoordCache: removing " << insets_.data_.size()
+//		<< " insets" << std::endl;
 	arrays_.clear();
 	insets_.clear();
 }
diff --git a/src/dociterator.C b/src/dociterator.C
index 2df577b5f4..49b8471f4a 100644
--- a/src/dociterator.C
+++ b/src/dociterator.C
@@ -57,6 +57,10 @@ InsetBase * DocIterator::nextInset()
 	BOOST_ASSERT(!empty());
 	if (pos() == lastpos())
 		return 0;
+	if (pos() > lastpos()) {
+		lyxerr << "Should not happen, but it does. " << endl;
+		return 0;
+	}
 	if (inMathed())
 		return nextAtom().nucleus();
 	return paragraph().isInset(pos()) ? paragraph().getInset(pos()) : 0;
@@ -440,13 +444,19 @@ StableDocIterator::StableDocIterator(const DocIterator & dit)
 }
 
 
-DocIterator
-StableDocIterator::asDocIterator(InsetBase * inset) const
+DocIterator StableDocIterator::asDocIterator(InsetBase * inset) const
 {
 	// this function re-creates the cache of inset pointers
 	//lyxerr << "converting:\n" << *this << endl;
 	DocIterator dit = DocIterator(*inset);
 	for (size_t i = 0, n = data_.size(); i != n; ++i) {
+		if (inset == 0) {
+			// FIXME
+			lyxerr << "Should not happen, but does e.g. after C-n C-l C-z S-C-z"
+				<< endl << "dit: " << dit << endl
+				<< " lastpos: " << dit.lastpos() << endl;
+			break;
+		}
 		dit.push_back(data_[i]);
 		dit.back().inset_ = inset;
 		if (i + 1 != n)
diff --git a/src/text.C b/src/text.C
index 05954f6ddc..6dcc706c3d 100644
--- a/src/text.C
+++ b/src/text.C
@@ -625,12 +625,11 @@ int LyXText::leftMargin(par_type const pit, pos_type const pos) const
 
 int LyXText::rightMargin(Paragraph const & par) const
 {
-	LyXTextClass const & tclass = bv()->buffer()->params().getLyXTextClass();
-
 	// We do not want rightmargins on inner texts.
 	if (bv()->text() != this)
 		return 0;
 
+	LyXTextClass const & tclass = bv()->buffer()->params().getLyXTextClass();
 	int const r_margin =
 		::rightMargin()
 		+ font_metrics::signedWidth(tclass.rightmargin(),
@@ -640,7 +639,6 @@ int LyXText::rightMargin(Paragraph const & par) const
 		* 4 / (par.getDepth() + 4);
 
 	return r_margin;
-
 }
 
 
diff --git a/src/undo.C b/src/undo.C
index d7a36941d0..08431d9ee2 100644
--- a/src/undo.C
+++ b/src/undo.C
@@ -27,10 +27,9 @@
 
 #include <algorithm>
 
-using std::advance;
-
 using lyx::par_type;
 
+using std::advance;
 using std::endl;
 
 
@@ -42,8 +41,7 @@ bool undo_finished;
 
 std::ostream & operator<<(std::ostream & os, Undo const & undo)
 {
-	return os << " from: " << undo.from
-		<< " end: " << undo.end
+	return os << " from: " << undo.from << " end: " << undo.end
 		<< " cursor:\n" << undo.cursor;
 }
 
@@ -62,6 +60,8 @@ void recordUndo(Undo::undo_kind kind,
 	Undo undo;
 	undo.kind = kind;
 	undo.cursor = StableDocIterator(cur);
+	lyxerr << "recordUndo: cur: " << cur << endl;
+	lyxerr << "recordUndo: undo.cursor: " << undo.cursor << endl;
 	undo.from = first_par;
 	undo.end = cur.lastpar() - last_par;
 
@@ -140,12 +140,12 @@ void performUndoOrRedo(BufferView & bv, Undo const & undo)
 }
 
 
-// returns false if no undo possible
+// Returns false if no undo possible.
 bool textUndoOrRedo(BufferView & bv,
 	limited_stack<Undo> & stack, limited_stack<Undo> & otherstack)
 {
 	if (stack.empty()) {
-		// nothing to do
+		// Nothing to do.
 		finishUndo();
 		return false;
 	}
@@ -154,10 +154,15 @@ bool textUndoOrRedo(BufferView & bv,
 	stack.pop();
 	finishUndo();
 
-	// this implements redo
+	// This implements redo
 	otherstack.push(undo);
-	DocIterator dit =
-		undo.cursor.asDocIterator(&bv.buffer()->inset());
+	// FIXME: This triggers the error in dociterator.C +454
+	// could the reason be that we rebuild the dit _before_ the
+	// contents is actually 'undone'?
+	// I.e. state now is 'A', state on undo stack is 'B'.
+	// dit is created according to positions from undo.cursor, i.e. B
+	// but current buffer contents is more likely 'A'.
+	DocIterator dit = undo.cursor.asDocIterator(&bv.buffer()->inset());
 	if (dit.inMathed()) {
 		// Easy way out: store a full cell.
 		otherstack.top().array = asString(dit.cell());
@@ -188,7 +193,7 @@ bool textUndoOrRedo(BufferView & bv,
 
 void finishUndo()
 {
-	// makes sure the next operation will be stored
+	// Make sure the next operation will be stored.
 	undo_finished = true;
 }