Just try reducing the number of simultaneous downloads (you don't have to delete prefs, just make the change & apply). Are you downloading huge files? When you open LW, give it half an hour to settle before you start downloading. Just try downloading a single file & see what happens.

This thread has lots of info about maximising dld/uld success:
http://www.gnutellaforums.com/showth...threadid=17321