quattro
Had huge problems when I moved house and started with BT's 8MB. They blamed every piece of equipment but their own. My connection kept dropping during the day with the message 'no dial tone' and would be out for days at a time then come back. If that is the message you're getting then I would say it is a fault with BT - spend a couple of hours with them on the phone on a regular basis and they might fix it (or quicker still go to India in person). The magic words - don't bother I'll change to NTL will prbably do the trick.
If all that fails blame the shorters, every one else does.