Try these and see if any get you up and going...
Try configuring your Norton Internet security and limewire..
Port Forwarding for the Norton Internet Security 2007
Try Port Forwarding your router...
Port Forwarding for the Linksys BEFSR41
Did you uninstall the Java 6.1 ?? If not uninstall it from your add/remove programs...
Last but not least try deleting your preference folder...
Fixes for Limewire when LW isn't operating as it should