It's incorrect that the *.gnutellanet.com host caches and that all of the *.bearshare.net host caches drop 0.4 handshakes. I did several 0.4 handshakes with a gnutellanet and a bearshare.net host cache a few minutes ago and got replies from both. I wrote the code myself and was watching it with tcpdump as well as within the code so I'm 100% certain of this. I'm not sure that they all handshake only 0.6 all of the time, and that they always will, but I do know that both gnutellanet.com and bearshare.net still respond to 0.4 handshaking on some basis.