If your router supports UPnP, you can just use that instead of a specific port. You can enable it in options.

If you go open status tab in options, you can get your globe back. If there is a wall in front of it you are firewalled.

You can be firewalled and still use LimeWire if you allow it in the firewall settings. Only use one firewall. Ain't familiar with McAfee, but if you have the windows firewall and another turned on at the same time, it is likely to cause problems.