Don't have the Windows & Norton firewalls running together...disable the Win & make sure the Norton's configured to allow LW.
PortForward.com - Free Help Setting up Your Router or Firewall

A couple of Vista users have been able to fix their connection problem by uninstalling both Norton & LW (don't uninstall LW via control panel, go all programs > LW & use the uninstall option), then reinstalling LW first & after that reinstall Norton.

Some people have had connection probs with the latest Java update, you could try this version instead. Download the JRE offline installer & remove any other Java versions before installing this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

What's the model of your Speedtouch?

Have you ever had connection probs in the past? It's just that Tiscali have been known to block p2p during peak hours. There's some info in the threads below
I have found a solution to getting Limewire to work with Tiscali
Tiscali blocking Limewire
can't connect between 5pm-11pm
Tiscali & Limewire
Connection Problem - with Tiscali.co.uk