Double-click the harddrive icon, open the Library, open the Receipts folder, then find the file: Install LimeWire.pkg, delete any you see. Then reinstall LW with the latest version.
Receipts folder sample image. Also be sure you're using Java 1.5, see
Setting up Java 1.5. However I think it now becomes default anyway. Let us know how it goes.
Oh & after installing LW, do a
SAFE Boot & Repair Permissions before running LW.