I see the "&t" too, using Safari 2.0.4. The Safari window does not need to be stretched, and does not disappear if the window is made very narrow. I only see the &t when viewing a list of topics within a forum (eg. "Apple News, Rumors & Discussion," "HOWTO & FAQs," "iPhone," etc.), I don't see it when at the top level of the forums (
http://macosx.com/forums/) or when viewing a particular thread. I had a look into the page source and found the &t appears at the very beginning, just before the document type declaration.