First try these options:
http://www.gnutellaforums.com/connec...t-connect.html
If you turn off your OSX firewall & LW still cannot connect, then chances are the problem is your modem/router.
Make sure your Mac LW is not using same connection or listening port as any other program or computer at your home. Check this on mac via LW preferences > Options > Advanced > Firewall.
You may need to port forward your Actiontec. To port forward you first need a static ip:
OSX static ip instructions
Then set up a port that you will use in LW. Perhaps choose one between ports 49152 - 65535 such as 64049 for both TCP & UDP
Last step is
Manual port forward instructions & sample image.