OK, running that software confirms your suspicion that it's something to do with the NIC or the TCP/IP stack on the Win2k box. What NIC is it?

The logging on the Receiver is output over serial. Unless you:

a) want to open up your Receiver
b) want to build the relevant level-convertor board
c) want to put together the correct cable.

...you'd better forget about that one .

You can get some logging out of the server by running

armgr /log:armgr.log

At this point, I'm suspecting some kind of firewall, other than the Norton stuff you've removed. Do you have any port-blocks set up in Win2k itself? To find out:

Control Panel -> Network Connections -> Local Area Connection -> Properties/General -> TCP/IP -> Properties -> General -> Advanced -> Options -> TCP/IP filtering -> Properties.