I know this is an ancient link, but I can't find a reference on here.
I opened http://www.smartphonemag.com/awards_2007/category.asp?catid=45#InternetRelayChat in Firefox 3.0.4, and was greeted by a wall of seemingly control characters, with a few pictures embedded. Thinking it was a browser issue, I opened it in IE7, which displayed a valid-looking HTML page. So I decided to look at the page source. Turns out that it's sending the full ASP source, which Firefox displays as a single line (which is why I didn't recognise it immediately, not on as little sleep as I had last night), IE7 apparently just discards the non-HTML part.