I've been disconnected about 4 or 5 times todaywhich is unusual. It may have been due to bittorrent causing my router to freeze but I cut back the number of connections to 50 (it's handled many more than that before) and I got disconnected again. It may also be the weather, I don't know.
No but there is a lot of trouble in the north of England at the moment with a BT fault. There is a list of exchanges affected posted in the Announcements / Sevice status forum.
It may be worth checking to see if you are on one of these exchanges