1. 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.)

2. You might also want to see this & do the suggested remedy: http://www.gnutellaforums.com/tips-tricks/57435-windows-xp-sp2-users-please-read-update-tcpip-sys-2006-06-15.html