Comment 17 for bug 627973

I think that's the same issue as the debian bug mentioned above, and is probably an incompatibility between using inetd to spawn openvpn and the ipv6 patch from Debian.

In openvpn 2.0, "Server Mode" can be used to serve multiple clients from a single port (with scalability in mind, so all client connections are routed through a single tun or tap interface). Have you considered switching your inetd-based setup to that model ?