This happens on any member's page I visit. The first thing I noticed is that the usual "Member List -> member name" link is almost completely covered up by the New Posts/Private Messages/FAQ/etc navbar. Then I noticed the black background behind that navbar is stretched too big; and that the Advanced Search link is kind of just floating above it. Finally, I noticed that the ad on the top of the page is not where it should be in relation to how it displays correctly on non-member-pages such as a thread page.
Seems like something is causing everything else to shift. I blame the ads again!
I've refreshed the page a few times and got several different ads to show, all yielding the same result. Using Firefox 8.0.