TalkTalk are known to shape bandwidth, which is probably why your downloads are so slow. A lot of people have had problems & yes, sometimes out of the blue after having no problems before
http://www.gnutellaforums.com/showth...light=talktalk

Apparently the only shape at certain times of day, check out the thread below
http://www.gnutellaforums.com/showth...light=talktalk