Are the hosts still sharing? I figure most gnutella clients just get turned on for a few hours, but requests aimed at them last for days in case they come back online. I usually just kill the stuck downloads in the queue (they can be resumed in Limewire and Acquisition) and try a new search. 10% success is what I expect

gnutella (doesn't Shareaza usually uses a different protocol--not gnutella?) has learned to block some hosts . Maybe your machine is one of the infected ones spreading the "awesome" stuff--lots of posts listing IP's and complaints. If your IP is dynamic and switched to a blocked one, that might explain no results.