space_silent your modem/router might not be UPnP capable. In which case you should probably manually forward a port for your device. To do so you MUST 1st set up a static ip or else it won't work. For instructions see below:

1. Set up static ip.
2. Forward port 6346 using these instructions: http://www.portforward.com/actiontec/701.htm
3. Within LW, see this: Manual port forward instructions & sample image & 2 posts after that.

Also make sure your firewall is properly configured to allow LW full access: http://www.limewire.com/english/content/firewalls.shtml