Same here - the problem is real and indeed very annoying. Unlike in the screenshot, for me the tabs often also cover the time remaining.
(And btw a similar problem in online chess: If the opponent is on vacation, the displayed vacation message is covering parts of the info directly below the board too.)

I'm on my laptop running Windows XP Professional 5.1.2600 and Firefox 13.0.1.
For a couple of weeks now, the tabs on the vote chess page have covered up some of the board. I have tried Firefox v13.0, Safari, and IE. Here is a Firefox screenshot:
Several other people have commented that they have similar problems. I can provide additional information if necessary.
Thanks.