Try the fixes in the post below.
If LW Will Not Connect

Start off by changing Java versions...a lot of people had connection issues with the Java version that you have Remember to uninstall all versions of Java (Add/Remove Programs) before installing a new one.

If that doesn't help, go through the other fixes carefully.

Also have a look at this post...even though it's very old, a few people have recently found that it's worked for them.
http://www.gnutellaforums.com/78282-post22.html

If you're sure that you've tried everything there & done it properly, have a look at port forwarding for your modem. The instructions are here.
Port Forwarding for the Zoom X5
Don't forget to set up a static IP address first! LW's lilstening port, port in the 'manual port forward' box & port forwarded within the modem setup should all be the same number