<html xmlns="http://www.w3.org/1999/xhtml" xmlns:math="http://www.w3.org/1998/Math/MathML">
<head>
<script>
function boom()
{
var textNode = document.createTextNode("a");
document.getElementById("mathy").appendChild(textNode);
document.documentElement.offsetHeight;
textNode.data = "bc";
}
</script>
</head>
<body onload="boom();">
<table><span></span><math:mrow id="mathy" /></table>
</body>
</html>