Ok, try deleting LW's preferences folder when LW's properly closed (check in task manager to make sure). Check out point 3 below for the location of that folder. Also look at point 2's location if you've used way older versions (4.9.33 or earlier) in the past.
Fixes for LimeWire
That folder within Application Data's hidden by default, so you'll have to show hidden files & folders to be able to see it.
Sticky: LimeWire Pref Folder in Vista
If that doesn't help, uninstall your version of Java & then reinstall. Make sure to use the JRE offline installer.
Java SE Downloads