Hi mushy (et al). I get this regularly, especially (but not only) when connected through a router. The workaround for me is to disable the ultrapeer preference and only connect as a leaf, which works well for searching and downloading--there are even some uploads too.

Although I haven't ruled out a hacker, this happens too often with all sorts of configurations of OS system, LW, router, firewall and IP.

OS 10.2.6, latest LW, 700MHz G3 ibook, static IP, 1Mbit/sec cable up and down.