OK...That's ruled out...
Check with these instructions to make sure you have your Norton and Limewire configured together properly..
Port Forwarding for the Norton Internet Security 2007
If it still wont connect try these fixes....
Right-click the Limewire icon and going to properties and change compatability setting to Windows 2000. (but only if you're using Windows 2000 or later.) Somebody reported changing to Windows NT compatibility fixed their problem despite not using that operating system version.
Right-click on the Limewire icon on the desktop and click on Run as. Then it should come up showing the current user and then switch it over to Administrator. (but 'only' if you're the admin of your comp.!)