Try the fixes here.
http://www.gnutellaforums.com/connec...tml#post298705

You could also try port forwarding for your router, the instructions are here.
Port Forwarding for the Linksys WRT54G
Don't forget to set up a static IP address first! LW's listening port, port in the 'manual port forward' box & port forwarded within the router setup should all be the same number

If nothing works, post back with your system details (see first thread for more info).