Error using JavaScript when editing source

I am having a fairly serious problem with v2.0 beta 2 on both IE6 and FireFox PR1 (Mac and PC). If I put the editor in source mode, then type the following:

Hello
<script language="JavaScript">
<!-- // Test content, anything can go here
//-->
</script>
World

Then click the 'source' button twice to toggle to preview mode and back to source mode, attempting to click the 'source' button a third time will fail in IE and give an error in FireFox. I am using XHTML mode, which is required for my project.

Cycling through preview mode in this way re-writes the code to (carriage returns added back in by me for clarity):

Hello
<script language="JavaScript">
<![CDATA[<!-- // Test content, anything can go here
//-->]]>
</script>
World

It appears that JavaScript causes the RTE to fall over, is this a known problem? Does anyone have any suggestions / workarounds?

Regards,
Austin.