Sometimes notices don't show up in Internet Explorer 7 and 8 (Win XP) and there is only a blank box (see the screenshot below). It's a little bit hard to reproduce, because it happends only from time to time.
Sorry for my late reply. I'm using Internet Explorer 9 on my own system and it took me a while to reproduce it on another computer. I was able to reproduce it with Internet Explorer 7.0.5730.11 (Win XP) both with the default style and here.
After I click "Log in or Sign up" and then click "Log in or Sign up" (without entering something) again the notice is visible.
Should be the same with Internet Explorer 8, but I don't have one here to test it right now.