Not seeing this in Firefox, IE, or Opera. Are you at any particular resolution or anything like that? Sometimes the CSS doesn't cooperate nicely at lower resolutions.
I'm at 800 x 600, didn't think that was particularly odd as far as resolutions go, but I could be wrong. I have seen this, however, on a completely different machine at work too (not that I read at work posts at work, heavens no).
Edit: Just tried it from yet another computer, same thing happening. That makes three now. :-/