I am not sure if this has been mentioned already, but while using firefox or microb sometimes there is an issue with the width. What I am seeing is that lines aren't being wrapped properly, so that much of a post will be missing. This is solved by moving to a different view, but now I am noticing it on the homepage as well. I'd also rather not use the classic white view. This also leads to losing the icons in the upper right corner for tagging a post as spam or whatever. It probably cuts out the bottom right ones too, but I didn't notice or look for that.

I've seen text wrapping issues (or missing text) when some large posts have been included inline in the forum posts. It's pretty annoying (on Opera/Firefox, works in IE though, eh), hope it gets fixed some day

On some forum I've seen solutions that if an image more wide than the "fixed" width is included, it will get it's own scrollbar. Possible with CSS.

ive had the above issue with firfox as well , along with some images not being displayed correctly