Doesn't work for application/xhtml+xml

We are building a shop in XHTML+RDFa and using the type application/xhtml+xml and when I try to test the speed I do not get the info expected:

Is it a problem with the tool?

IE 7 and 8 don’t know what to do with the page. Have you tried loading it in IE? I get a file download dialog which is why WebPagetest fails on it.

I asked 3 guys besides myself and all have tested with IE8 and I tested on IE 7 and no problems. I have a script that can solve any problems like that, so I will just implement and when ready I will try again.

Thanks for the heads up.