IE9 and application/xhtml+xml

All major browsers today support mimetype "application/xhtml+xml":
IE9+, Safari, Firefox, Opera, Chrome. They all render XML webpages
incrementally. Very nice.

They all, except IE9, show an error message if there is a well-formedness error.

But IE9 switches to HTML parsing instead of showing an error message!

Question. IE9's behavior is in my opinion in opposition to what the
spec demands. But is IE9's behavior bad? I find it confusing but could
it be the way forward to get "application/xhtml+xml" more widely
adopted?


Cheers
Jesper Tverskov

http://www.xmlplease.com
http://www.xmlkurser.dk
http://www.xmltraining.net