When you port forwarded the Motorola, did you set up a static ip address first? This is a must, else the port forward rules would need to be removed & redone.

Have you set up an exception for LW in the McAffee firewall? Setting up an exception for LimeWire in your software firewall (click in link)

Did you disable XP's firewall?

Try the suggestions Birdy made here: If LW 5 Will Not Connect