Try varying your search terms & also use the All Types search rather than just Audio. Maybe, set your preferences (tools > options etc) to show all qualities & all speeds. Try to download from multiple sources. If you're looking for rarer files, try searching at different times of day. It always varies a bit as people go offline & new hosts come online.

A few tips here
http://www.gnutellaforums.com/showth...#post%20139889