Well prepare to be bombarded with "OMG IE SUX GET TEH BEST BROWSER EVAH TEH FIREFOX NOW YOU STOOPID NOOB!11" post any minute now.

But yeah, it's exactly what Vyk said...you need to kill adware/spyware, which is what's doing that...plus if you have windows xp and you're getting popups, you've either turned the blocker off or that's some really evil spyware (which it probably is).