Welcome to the Gnutella Forums, Blindpilot.
Using two firewalls can cause issues with Less Protection. Try disabling the Windows firewall and give LW Full access through Nortons Firewall.
You also may need to forward a port for the Belkin Router. See Link
PortForward.com - Free Help Setting up Your Router or Firewall
Another thing that comes to mind is your ISP. Seems that they are really cracking down on P2P in the UK. Might give them a jingle and see if they will give you an
honest response.
Hope this Helps.