I can't find any port forwarding info (or much info at all) about your router. The Belkin site's no help as the user guide & quick start manuals never load
So I can't even find out whether it has a firewall (most routers do) or supports UPnP. Does your manual tell you anything about that??

Which version of Java are you using (in LW Help > About LW will show you)?

Try removing any rules for LW from within Vista's firewall. Then restart your computer & add new rules.

Go to LW's tools > options > advanced > firewall. Change LW's listening port from 6500 to 65000 > apply > ok.

Do you just have the 'manual port forwarding' ticked within LW's tools > options > advanced > firewall or do you actually have a port forwarded within your router's setup (by logging into your router & changing settings)?

Did you have any problems finding the preferences folder? After you deleted the prefs folder, did you go through LW's setup wizard all over again?

Go & find your gnutella.net file. Hover your cursor over the file - how big is it?