Update your Java to the latest version. Before installing that latest update, remove any other versions of Java that you have (see thread below for a link to Java).

Have you also deleted the preferences folder within Application Data? That's the folder that's hidden by default. After you deleted the preferences folder(s), did you go through the setup wizard again when LW was started?

Have a look at this thread, even if you've tried these fixes before, just go through things again slowly.
http://www.gnutellaforums.com/connec...tml#post298705

If nothing's working, please post with your system details (see thread above for more info).