Try deleting your LW Preferences folder whilst LW is closed; instructions here: Point #2 & 3 in Fixes for Limewire (sample image included at bottom of page.)

http://www.gnutellaforums.com/genera...der-vista.html

Make a note of all your settings first however, because once you delete this folder & re-open LW, you will need to reset all options again such as days to keep incompletes, location of shared folder again, etc.