Have you tried restarting LW?
Check the location of your saved folder. In LW tools > options > saving shows you the location. By default it's C:\Documents and Settings\your name\Shared. Have you changed the location of that saved folder?

If you haven't changed the location of your saved folder, try deleting LW's preferences folder when LW's properly closed. See point 3 below (also point 2 if you've used much older versions of LW in the past...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 & reset things afterwards.

Sorry for the Vista comment that you'll see in your email notification...I can't read today!!!