Try creating a javascript function which runs this:
document.getElementById("youriframeid").contentWindow.location.reload(true);
Or maybe use an HTML workaround:
<html>
<body>
<center>
<a href="pagename.htm" target="middle">Refresh iframe</a>
<p>
<iframe src="pagename.htm" name="middle">
</p>
</center>
</body>
</html>
Both might be what you're looking for...