Check out LOTR's advice here.
http://www.gnutellaforums.com/292886-post2.html

Try deleting 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 change all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.

You'll know if you've deleted the preferences folder properly...when you start LW, you'll go through the setup wizard again.

In case you're using Vista: LimeWire Pref Folder in Vista