I finally got around to upgrading to WinGate 6 something ("revision" just assures me that I'm running the "latest version") from 2.something, and broke my AtomTime path to NTP. I don't see what setting I've allowed to be different between the two installations.
AtomTime allows one to specify a proxy IP and port, which is set to 80 in the old version. Neither that nor 123 work in the new configuration. According to the developer's notes, the error says AtomTime is finding the time server but not receiving a reply.
If I tell AtomTime to *not* use the proxy, it promptly connects and obtains the correct time. This is true of computers on the internal network as well as the WinGate server.
The WinGate server is on an XPsp3 machine; most of the others are on XPsp2.
When I get that fixed I'll probably have TiVo's connection to make work. Its first whimper will be a need for icmp both ways, plus a bunch of ports. Horribly designed, but you're not allowed to mention that in the Halls of TiVo.