Os X 10.3.5
 

Has anyone upgraded to 10.3.5 only to have Limewire stop working? Ours was working fine until the upgrade now it won't even open.

You could try deleting LimeWire and then downloading it again. I hope this solves your problem.

Thanks for that idea. It's been done several times without success.

You have to delete it completely. Even it's preferences. Run a search for Limewire in the Finder and delete everything.
You can also try uninstalling, dlding and reinstalling Java. It could be that with the upgrade came in a new Java that got corrupted in the dld (even though I'm pretty sure that Jaguar and Panther use the same Java)