Ouch! Tiscali is known to filter p2p use in some areas! Which means as soon as they detect you have p2p they slow your speeds. They use special softw to detect & do this. See: http://www.gnutellaforums.com/showth...threadid=33712

But this might not apply to you. (By the way they never tell you!)

Try deleting LW's preferences folder; instructions here: Fixes for Limewire (although I think you already tried that.)