An installation problem probably. Either with Java or LW. I have suspicion it's due to previous version of Java still having some components on your computer. It's always best to install both using the "Offline" installers, not over the internet. Remove all versions of Java & then reinstall; Download Java software from Sun Microsystems

Download the offline version of LW as well, then install.

BEFORE you reinstall LW (the installer will remove previous version), do this: (1) Try deleting your LW Preferences folder whilst LW is closed; instructions here: Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)
(2) Run this small but useful utility: Crap Cleaner