I'm convinced that BT (British Telecom) are restricting use of P2P during the day. I can't get the usual Gnutella ports (6436 - 6348) to work at all, and shifting to another port sometimes only seems to work for a short while before downloads either slow to a crawl or stop altogether. Other times other ports seem OK albeit downloads are slower than normal. From about midnight I can download with no problem, mornings can be hit and miss. Other people I know who use BT and LW have noticed similar things.

There's nothing official and BT have a dreadful customer service helpdesk that it's not worth the effort contacting them. But this problem has existed for a while now