You have NTL by any chance? I get mega speed downloading from newsgroups and from well seeded torrents all the time, but sometimes (alot of the time actually!) the internet speed itself for sufing seems really slow, ive frequently checked everything along the lines of virus/trojans or spyware, clearing browser cache etc. etc. but everything is fine everytime, i think its something to do with the way NTLs proxy works maybe? I find with firefox things are much better (not to mention its a great browser anyway far better than IE)