<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style id="ss" type="text/css">
#o {
height: 65px;
}
</style>
<script type="text/javascript">
function boom()
{
document.getElementById("ss").disabled = true;
document.documentElement.offsetHeight;
document.getElementById("ss").disabled = false;
}
</script>
</head>
<body onload="boom();">
<div style="-moz-column-width: 0;">
<colgroup></colgroup>
<div>
<div id="o" style="float: left;"></div>
<div style="clear: both;">A B<div style="float: left;"></div></div>
</div>
</div>
</body>
</html>