Been well discussed lately .. the apple java update broke LW 5.1
What works for most of us is LW 5.2.2 or any version of LW 4
LimeWire 5.2.2 (Beta) - Lime Wire _ or _ http://www.gnutellaforums.com/downlo...downloads.html. However if you were to go back to LW 4, you would need to first remove the install limewire.pkg file from the OSX -> Library -> Receipts folder else the system will not let you install an older version.

BTW the LW Beta 5.2.2 is quite stable & has some nice improvements.