Don't go doing anything too drastic just yet!
Have you tried un-installing your java runtime engine and your copy of Limewire at the same time and then re-installing both from the start. It's best if you can install the Java RTE in the offline state which means downloading the larger 15 MB package from Sun microsystems and give that a go. Quite often people have had to re-install both at the same time to have success with their problem. I'm not sure why this works but it seems to work for a lot of people to install the java RTE manually and then Limewire also manually before they have success. Read as many of the "Stickies" at the top of the forums and hope there is an answer there that might help you. Perhaps some of the more experienced helpers may step in here and help you out, but either way. Let us know how you go.
Good Luck!