Small things - I hope they haven't been mentioned:
1. When I click on a member's "view posts", page 1 of the results is in message format while page 2 is in topic format. Then, if I return to page 1 from page 2, they remain in topic format.
2. Many times, but not all, when I go to a page in the forums (seems to be random) the page loads so that the entire forums block (messages, avatars, etc) appears below the left-hand menu box, rather than to the right of it, leaving a LARGE blank area. Of course, I can't get it to happen right now, so I can't do a screen shot. Using XP and IE6.