AFAIK BearShare after version 5 does not run on the Gnutella network. It runs on a different 'commercial' network.
http://www.gnutellaforums.com/open-d...sabotaged.html discusses briefly what happened. A fuller explanation for Bearshare, a sabotaged ShareAza & other programs explained here
The Story: Shareaza, iMesh, RIAA, and Recent Events.
FW 4 is still fine to use. I'd recommend sticking to it.
BearShare 5 is still fine to use. Link to a slightly upgraded version & connection fix linked at top of the main
BearShare forum page on the forum. The main BS program has not been updated in several years though.
Other options include
Phex and
GTK-Gnutella as programs still being actively developed.