I've reviewed this thread. Actually Westell devices are not that reliable run in UPnP mode from experience on these forums. I'd recommend port forwarding the router.

Instructions (this must be done in this order):

1. Set up a Static ip address for Windows XP

2. Port Forwarding Limewire on the Westell D90-327W15-06. When you port forward, choose both TCP & UDP. Preferential to do a separate port forward rule for each of UDP & TCP, using the same port.
Note: The instructions for LW on that page refer to LW 4. For LW 5, see sample image here Manual port forward instructions & sample image
Which port to use? I'd recommend choosing a port number between 49152 - 65535. Whichever one you choose should be the one you port forward & put into the connection & listening settings within LW.