This looks like the best place to put this.
On the main page and on the topic pages (where you read posts), it stretches to about twice the width of the screen, but this doesn't happen on topic list pages (after clicking on which section you want), or when posting a reply (like I'm doing now).
This doesn't happen in Firefox, and if it happened in IE there would be a whole lot of complaints.
I just thought I would post it, since it's kind of annoying scrolling side to side to read the posts, and I don't want to switch to Firefox for just one site. Maybe someone can fix it.
EDIT: Oh, yeah, and when posting a new topic in Opera, the forward to the topic page is broken. The information gets sent to the server and the topic gets posted, but the page won't change.