<html xmlns="http://www.w3.org/1999/xhtml" xmlns:m="http://www.w3.org/1998/Math/MathML">
<head>
<script type="text/javascript">

function boom()
{
  var mtd = document.getElementById("mtd");
  var ns = document.createElementNS("http://www.w3.org/1999/xhtml", "span");
  var nt = document.createTextNode("foo");
  ns.appendChild(nt);
  mtd.appendChild(ns);
  mtd.setAttribute("rowspan", "0");
}


</script>
</head>

<body onload="boom();"><m:mtd id="mtd" style="display: table-footer-group"><m:mi /></m:mtd></body