Have you been using Java 1.6.0_02 for a while? Some people have had trouble with that version. Try this older Java instead. Use the JRE offline installer & remove your current Java version(s) before you install this one.
Archive: Download Java 2 Platform Standard Edition (J2SE) 5.0 Update 11

Now reinstall LW & make sure to use the offline installer. When you've clicked to download LW & the download box pops up, cancel it. You'll see an option to download the offline installer

If things are still stuffed, delete LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used older versions of LW in the past (there could be a folder in either location).
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things.