Don't disable your firewall, configure it to allow LW
User Cant Connect - LimeWire

Some people have had connection issues with that latest Java version. Try this one instead, it's easy to reinstall the latest version if it turns out that Java's not the problem!
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11
Download the JRE offline installer & remove any other Java versions before you install this one.

Try port forwarding for your Westell, the instructions are here.
Port Forwarding for the Westell 6100
LW's listening port, port in the 'manual port forward' box & port forwarded within the modem should be the same number.