*Initial thought with RPC error is MTU; but need some more details
1. What version of WinGate / VPN Only are you using? The latest is 6.1 / 2.1 ... If you are not using those versions, you may want to consider upgrading.
2. a) Are the Win98 PCs VPN Joiners or VPN Participants to the VPN Host.
2. b) Are the Win2k PCs VPN Joiners or VPN Participants to the VPN Host
2. c) Are the WinXP PCs Joiners or VPN Participants to the VPN Host
2. d) What about this other Win2k PC you are talking about; is it the VPN Host?
3. Have you disabled any securtiy suites / firewalls for the sake of testing?
4. I notice you have another post, similar to this on the 14th Oct; did you resolve that; what was the problem?
http://forums.qbik.com/viewtopic.php?p=19323#19323
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VPN Host: The Host is like the Server, and runs WinGate / VPN only software.
VPN Joiner: The Joiner is the client, and runs WinGate / VPN only software.
VPN Participant: Are computers that DO NOT run the WinGate or WinGate VPN only software, but participate in the VPN