LimeWire folks have told BearShare that LW drops queries by hash, which are used in a limited way by BShare. I don't recall all the details (it's a pain to find the posts easily on http://groups.yahoo.com/group/the_gdf/ ). However, the two groups look like they cooperate so I doubt there's anything sinister going on.

(Bearshares also use specific code to securely connect to each other, but I don't know if that would register in the Connection stats).