I have to warn you Tiscali is reknown as being anti p2p sharing world over.

Norton & Windows firewalls usually clash, resulting in less security not more. So disable window's firewall, & make a firewall rule allowing LW through on the Norton firewall; roughly like this: Configuring Norton Internet Security.

Go to LW's menu bar, Tools > Options > Advanced > Firewall, change the listening port to one between 49152 - 65535. Then go to Tools > Options > Advanced > Performance & disable all those options. Press apply & ok buttons. Then go to File menu select Disconnect. Wait a minute or so. Then File menu -> Connect. See if it connects. If not, then try these options: If LW Will Not Connect (click on the blue link) (especially replacing the gnutella.net file.)

If none of that works, you could try port forwarding your router. There are instructions we can give you. I will not be around but someone else will give them to you. Most important thing when port forwarding is setting up a static ip which is the very first thing you need to do. But think about that later.

Oh btw, make sure LW's listening port is not the same as any other LW on your network.