I;ve seen problems like that in the past where IE refuses to work right on a site. And thatks to MS integration, there is no way to completly restart IE without a restart of the OS. Mozilla has had a few problems like this as well, but all I need to to there is close all my windows and close the quick launcher.

(/me has painful flashbacks of Netscape 4 and it's problem like this, and the need to use taskmanager to kill it)