Ouch. So many people are having problems with Tiscali lately. They do shape p2p traffic during peak hours & are possibly blocking as well but I can't find any proof of that. Here are some threads to read (you'll probably find more info via Google as well).

http://www.gnutellaforums.com/showth...hlight=tiscali
http://www.gnutellaforums.com/showth...hlight=tiscali
http://www.gnutellaforums.com/showth...hlight=tiscali
http://www.tiscali.co.uk/forums/show...2&page=3&pp=15