I found this post in a Google search:
but it was closed and I wanted to post the fix (at least what worked for me).
I had a similar problem - in IE7/8 the text bled over under the right side menu - and further down the page it bled over into the empty space and looked aweful, but in FF3 everything was fine. It turns out a new post was made with a long URL posted (rather than hyperlinking). I took the URL out and hyperlinked a few words instead - that fixed it. Hope this helps someone else. :)