The only thing I can suggest is for you to un-install the Java RTE and then re-install it from the beginning. If you've already done that and that didn't work, try un-installing both the Java RTE and your copy of LimeWire and re-installing them and see if that solves your problem.
Other people have had similar problems and they solved it by re-installing both applications at the same time.
If that doesn't work come back here and post another message explaining what you have done and hope that someone else with more experience can guide you to a solution.
Good Luck!