OK ciclown--I'll see if someone in the know can take a look. Googling for the error shows a number of others.

In the meantime, reinstalling java might help.
Apple - Downloads - Application Updates - Java for Mac OS X 10.5 Update 2

Another long shot is using an alternate method of opening: i.e, clicking the icon directly from the Application/LimeWire folder,

or opening from the terminal (skip if you aren't comfortable with this)
control click the LimeWire.app icon, choose Show Package Content, then open Contents, MacOS until you find the file called LimeWire

open a new Terminal window, and then drag the Limewire file onto the terminal window.

Hit return and the Terminal will try to start LimeWire. If it works, great; if not you should get the errors printed out in terminal.