diff --git a/src/mathed/math_atom.C b/src/mathed/math_atom.C
index 217f109069..cedad2b5c5 100644
--- a/src/mathed/math_atom.C
+++ b/src/mathed/math_atom.C
@@ -206,7 +206,8 @@ MathScriptInset * MathAtom::down() const
 
 int MathAtom::dy0() const
 {
-	lyx::Assert(down());
+	if (!down())
+		return ndes();
 	int des = down()->ascent();
 	if (hasLimits())
 		des += ndes() + 2;
@@ -218,7 +219,8 @@ int MathAtom::dy0() const
 
 int MathAtom::dy1() const
 {
-	lyx::Assert(up());
+	if (!up())
+		return nasc();
 	int asc = up()->descent();
 	if (hasLimits())
 		asc += nasc() + 2;
@@ -252,19 +254,13 @@ int MathAtom::dxx() const
 
 int MathAtom::ascent() const
 {
-	int asc = nasc();
-	if (up()) 
-		asc += hasLimits() ? up()->height() + 2 : up()->ascent();
-	return asc;
+	return dy1() + (up() ? up()->ascent() : 0);
 }
 
 
 int MathAtom::descent() const
 {
-	int des = ndes();
-	if (down()) 
-		des += hasLimits() ? down()->height() + 2 : down()->descent();
-	return des;
+	return dy0() + (down() ? down()->descent() : 0);
 }
 
 
diff --git a/src/mathed/math_scriptinset.C b/src/mathed/math_scriptinset.C
index 019c045e37..9e8732797e 100644
--- a/src/mathed/math_scriptinset.C
+++ b/src/mathed/math_scriptinset.C
@@ -33,6 +33,8 @@ void MathScriptInset::metrics(MathStyles st) const
 	width_   = xcell(0).width();
 	ascent_  = xcell(0).ascent();
 	descent_ = xcell(0).descent();
+	//lyxerr << "MathScriptInset::metrics: w: " << width_ << " a: " << ascent_
+	//	<< " d: " << descent_ << "\n";
 }
 
 
diff --git a/src/mathed/xarray.C b/src/mathed/xarray.C
index 4aa396bfa8..1a31caee9f 100644
--- a/src/mathed/xarray.C
+++ b/src/mathed/xarray.C
@@ -36,6 +36,8 @@ void MathXArray::metrics(MathStyles st) const
 		descent_ = std::max(descent_, p->descent());
 		width_  += p->width();
 	}
+	//lyxerr << "MathXArray::metrics(): '" << ascent_ << " " 
+	//	<< descent_ << " " << width_ << "'\n";
 }