SP2 Slow IE Normal Firefox

After installing SP2, my connection speed using IE is clocked at 80Kbs but when I use Firefox my connection speed is clocked at around 1.25Mbs (normal) BIG difference!!! Normally I wouldn't care since I prefer Firefox but as we know IE affects much more than just web surfing. I can't tell you how many things I've tried to fix this. Has anyone else heard of this or are experiencing this?? Is there a fix?? Also, I can't log into .NET Passport using MSN Messenger since the SP2 install. Yet another big annoyance that seems to be somehow linked to IE. Please Help Me!!!