You should configure these firewalls to allow LW full access. For Sygate see link at bottom of this page: http://www.limewire.com/english/content/firewalls.shtml
& for Norton see: Configuring Norton Internet Security

The routers may themselves have internal firewall but if you don't have access then ... we'll hope it doesn't affect things.

I could be tempted to get you to update to LW 4.4.x b/c it has improved firewall detection & ability to work with it so to speak. It has UPnP detection if your equipment uses that technology.