Remove your old Java version & reinstall using the offline installer here
http://www.java.com/en/download/manual.jsp
If that doesn't fix things, try deleting the preferences folder (points 2 & 3 here) when LW is closed
Fixes for LimeWire
(this will kill your settings within tools > options. You'll have to go back & reset everything afterwards)
If still no joy, reinstall LW using it's offline installer here
http://www.limewire.com/english/content/download.shtml