Hmmmm just a thought I know this may sound like a PITA, but here goes.

Uninstall LimeWire and Java. Open windows explorer and search for anything LimeWire and Java. If you find any thing delete it. Run a registry checker/cleaner. If you don't have one search(upper right) the forums for one. There are a few links to some that are decent.

After you have cleaned the registry shut down and restart the comp.

Then reinstall Java and LimeWire in that order.

I'm thinking something may have gotten messed up in your registry.

Like deacon72 mentioned a well maintained comp. is essential to proper operation of programs. I have messed up my registry in the past installing and unintsalling programs before. For some unknown reason not all the registry entries get removed that should have been. A registry cleaner has normally fixed these problems.

Best of luck