I've read posts from other Jaguar users saying that Limewire 2.5.5 runs fine on their system, so the OS isn't necessarily the problem.

This type of error seems to appear periodically on all systems and I haven't read of any specific fixes. I can only suggest the typical groping in the dark solutions (if one doesn't work, try the next):

1. Reinstall Limewire
2. Reinstall Java & Limewire
3. Download & reinstall Limewire 2.5.5
4. Try and download a previous version of Limewire