Make sure your software firewall is properly configured. Make sure you only have one Active firewall; Firewall configuration instructions (click on link)

BTW after setting up UPnP you will need to relaunch LW for it to work.

If still problems you might be better to port forward instead of using UPnP. See instructions here http://www.portforward.com/english/r...2/Limewire.htm which is equivalent to your model for doing this.