do you guys have BT internet ? why i ask is, I have just solved the very same problem by installing a home wireless home network and dumping the BT software and tacky modem for a wireless/modem router. i know you might not be able to fix the problem the same way as me, but i would at least try getting a new modem from a third party.
the problem isnt the internet it is the P2P file sharing even after ares or kazaa had been shut down for like 5 minutes and all u/l & d/l were shut down my pc would not log off properly.
the next time i would reboot i would have install the drivers on my pc or laptop again which was frustrating as hell. when you phone BT up all they have to say is blah.
a friend of mine uses p2p software and he has never had this problem, the only thing differnt about my friend was that he uses AOL and not BT