I was adding GNUTELLA/0.6 connects to Salmonella, and I had to test it (of course).
So since my main client I use is Gnotella 1.0.3, I tried connecting to that. It is a relatively old client, and no further development seems to be done on it.. should give a good testbed.
Well whaddayaknow.. it connects at 0.6 correctly! Go Gnotella!
So I had to test it on my own client

(it doesnt handle 0.6 incoming connections *yet*)... this seemed to work much better downgrading my connection to 0.4 :-)
Any more hidden features?