There is nothing wrong with your Java installation, nor is there anything wrong with SP2, and there is nothing wrong with Limewire either.

Yes, the files are intentionally corrupted. But it is not MS that is doing it. It is RIAA. They have been recently renting space on servers and placing thousands of intentionally corrupted files onto P2P networks to discourage downloading of copyrighted material.

So don't worry, there is nothing wrong with your Windows installation, or your Java installation, or your Limewire installation.