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.