This may be the same problem that some other people are having, which I haven't yet been able to get to the bottom of - pretty annoying!
There are a few things to try in these forum posts:
viewtopic.php?f=10&t=2792viewtopic.php?f=10&t=2644viewtopic.php?f=10&t=2741Check that Internet Explorer itself is working correctly - does it display web pages properly, and what about when you trying playing one of the games on this site online? Also you could try disabling add-ons, maybe even try temporarily disabling any anti-virus software.