diff --git a/src/ChangeLog b/src/ChangeLog
index 5117a5a8fd..faf4cd5b5f 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2005-10-09  Georg Baum  <Georg.Baum@post.rwth-aachen.de>
+
+	* text3.C (mathDispatch, dispatch): Dont' record undo steps that don't
+	change anything.
+
 2005-10-11  Martin Vermeer  <martin.vermeer@hut.fi>
 
 	* BufferView_pimpl.C: comment layout change
diff --git a/src/mathed/ChangeLog b/src/mathed/ChangeLog
index 37ef546e50..d0bb6cea54 100644
--- a/src/mathed/ChangeLog
+++ b/src/mathed/ChangeLog
@@ -1,3 +1,8 @@
+2005-10-09  Georg Baum  <Georg.Baum@post.rwth-aachen.de>
+
+	* math_nestinset.C (doDispatch): Don't record undo steps when
+	inserting characters of a macro name (see comment)
+
 2005-10-04  Georg Baum  <Georg.Baum@post.rwth-aachen.de>
 
 	* math_macro.C (editXY): new, fix crash (bug 2060)
diff --git a/src/mathed/math_nestinset.C b/src/mathed/math_nestinset.C
index d9313471af..b12a44ad16 100644
--- a/src/mathed/math_nestinset.C
+++ b/src/mathed/math_nestinset.C
@@ -651,11 +651,22 @@ void MathNestInset::doDispatch(LCursor & cur, FuncRequest & cmd)
 		break;
 
 	case LFUN_SELFINSERT:
-		recordUndo(cur);
 		if (cmd.argument.size() != 1) {
+			recordUndo(cur);
 			cur.insert(cmd.argument);
 			break;
 		}
+		// Don't record undo steps if we are in macro mode and
+		// cmd.argument is the next character of the macro name.
+		// Otherwise we'll get an invalid cursor if we undo after
+		// the macro was finished and the macro is a known command,
+		// e.g. sqrt. LCursor::macroModeClose replaces in this case
+		// the MathUnknownInset with name "frac" by an empty
+		// MathFracInset -> a pos value > 0 is invalid.
+		// A side effect is that an undo before the macro is finished
+		// undoes the complete macro, not only the last character.
+		if (!cur.inMacroMode())
+			recordUndo(cur);
 		if (!interpret(cur, cmd.argument[0])) {
 			cmd = FuncRequest(LFUN_FINISHED_RIGHT);
 			cur.undispatched();
diff --git a/src/text3.C b/src/text3.C
index 2a7b879f3f..671f7e6cc4 100644
--- a/src/text3.C
+++ b/src/text3.C
@@ -136,17 +136,20 @@ namespace {
 
 		if (sel.empty()) {
 			const int old_pos = cur.pos();
-			cur.insert(new MathHullInset);
+			cur.insert(new MathHullInset("simple"));
 			BOOST_ASSERT(old_pos == cur.pos());
 			cur.nextInset()->edit(cur, true);
-			cur.dispatch(FuncRequest(LFUN_MATH_MUTATE, "simple"));
 			// don't do that also for LFUN_MATH_MODE
 			// unless you want end up with always changing
 			// to mathrm when opening an inlined inset --
 			// I really hate "LyXfunc overloading"...
 			if (display)
 				cur.dispatch(FuncRequest(LFUN_MATH_DISPLAY));
-			cur.dispatch(FuncRequest(LFUN_INSERT_MATH, cmd.argument));
+			// Avoid an unnecessary undo step if cmd.argument
+			// is empty
+			if (!cmd.argument.empty())
+				cur.dispatch(FuncRequest(LFUN_INSERT_MATH,
+				                         cmd.argument));
 		} else {
 			// create a macro if we see "\\newcommand"
 			// somewhere, and an ordinary formula
@@ -155,9 +158,8 @@ namespace {
 			if (sel.find("\\newcommand") == string::npos
 			    && sel.find("\\def") == string::npos)
 			{
-				cur.insert(new MathHullInset);
+				cur.insert(new MathHullInset("simple"));
 				cur.dispatch(FuncRequest(LFUN_RIGHT));
-				cur.dispatch(FuncRequest(LFUN_MATH_MUTATE, "simple"));
 				cur.dispatch(FuncRequest(LFUN_INSERT_MATH, sel));
 			} else {
 				istringstream is(sel);
@@ -1271,9 +1273,8 @@ void LyXText::dispatch(LCursor & cur, FuncRequest & cmd)
 	case LFUN_INSERT_MATH:
 	case LFUN_INSERT_MATRIX:
 	case LFUN_MATH_DELIM: {
-		cur.insert(new MathHullInset);
+		cur.insert(new MathHullInset("simple"));
 		cur.dispatch(FuncRequest(LFUN_RIGHT));
-		cur.dispatch(FuncRequest(LFUN_MATH_MUTATE, "simple"));
 		cur.dispatch(cmd);
 		break;
 	}