I wonder if it has anything to do with the fact that you must serve XHTML 1.1 as real XML instead of using the text/html mime type, which I assume you are doing if you have it working in IE as it does not support XHTML served in the correct way.
That's an absolute stab in the dark, and probably nothing to do with it in fact, but I thought it might be worth considering. Good luck getting to the bottom of it. Joel Birch.
