Were you able to use LW before, or have you just installed it? Does the mouse work ok with other programs?

What version of Java are you using? Try reinstalling this version of Java. Use the JRE offline installer & remove your current Java version before you install this one.
Java SE Downloads - Previous Release - JDK 5

You could also try deleting LW's preferences folder when LW's properly closed. See point 3 here & also point 2 if you've used much 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.

Have a look at this thread & see if anything helps.
http://www.gnutellaforums.com/genera...-disabled.html

If those things don't help, let us know what brand & model of mouse you're using & any other details that might help (eg is it wireless?).