See http://www.gnutellaforums.com/showth...threadid=39612 & see if it applies to you. Also try changing your LW's compatibility to win 2k; instructions here: Fixes for Limewire
You could also try deleting the LW preferences folder whilst LW is closed (instructions in link above.)

If this doesn't fix it, then I'd recommend uninstallling it from the Start menu >Programs>LW>Uninstaller, then re-installing it from here: http://www.limewire.com/english/content/download.shtml