<!DOCTYPE html>
<html>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=507487
-->
<head>
<style>
#content > * {
  display:block; width:100px; height:100px; background: purple;
}
#content > teST {
  display:block; width:100px; height:100px; background: green;
}

#content > test {
  display:block; width:100px; height:100px; background: blue;
}

</style>
<script>
  function f() {
    document.getElementById('content').appendChild(document.createElementNS("test", "test"));
    document.getElementById('content').appendChild(document.createElementNS("test", "teST"));
    document.getElementById('content').appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "test"));
    document.getElementById('content').appendChild(document.createElementNS("http://www.w3.org/1999/xhtml", "teST"));
  }
</script>
</head>
<body onload="f();">
<div id=content></div>
</body>
</html>