On the one hand I'm very happy to see that you're investigating in the Win2k-crash problem - on the other hand I've got sad news for you (or at least for other Win2k users):

The test release #3 doesn't fix the crash problem, in my case it even made it worse. I'm running one 2xPII 350 and one 2xPIII 700, both on Win2kSP2, both SMP systems and both crash during the first 10 seconds.

Oh, and both are behind a firewall. Number one at work behind a "everything-except-port-3128-is-blocked" firewall (useless for Gnutella but I installed it just to confirm the instability of Gnucleus.exe), and system #2 at home behind a NAT server which usually has no problems with all possible P2P/Gnutella/WinMX...
Maybe this is of interest for you.

Thanks for your efforts and let's hope Gnucleus will reign on Win2k systems soon, too