I tried to go to msn.com. It came up as text only. The top of the page had the following lines:
Why does MSN look like this?
Your browser cannot find our style and presentation information. You’re welcome to use the page as is, or upgrade your browser to its latest version.
So not only do some non-MS browsers have trouble with MS web pages, but so does IE!
(I'm required to use IE 5.5 at work, by the way)