One thing you need to do is setup the PC with a static IP address, instead of one assigned by the Router. Your LinkSys documents should explain how to do this - if you're still unsure, just ask here. If you haven't done this very often, I'd highly recommend writing down the current settings before you change it.

Once you've done that, go to the admin page where you saw port forwarding. For the port range, you enter 6346 - 6347. For the protocol, TCP should be sufficient but you can leave it at "Both". And for the IP address, you can only enter the last digit, which would be that of the static IP address of your PC running Limewire.

Once that's is done, you should be able to recive incoming connections on LimeWire, including direct upload requests.

-- Mike