Re: Slow Internet
If you suspect it's your OC, why not downclock long enough to find out? I doubt it it, but anything is possible.
Try Opera and IE, also, to make sure your browser isn't jacked. It never hurts to boot into safe mode and run HiJackThis, Spybot, Adaware, an AV scan, and remove any crud. Just make sure to disable system restore before you boot into safe mode so that there is no residual junk left in there.
Or it could be a DNS issue like EG said. Have you tried using the IP's to access sites?