VPN inside the router

[mmX]

I set up the poptop-ipkg-package successfully. It is possible to dial in from WAN and LAN side.
There is a little problem with dial in from a WinXP clients, they must repeat the dial-in
process two or three times until they get a IP. Does anybody has the same problem?
But it's not as bad as that.

The real problem is another. If the Client dials in successfully he gets a valid IP-address.
The Client can connect to the webinterface from the wl500g as well, but not to the dropbear or telnet server.

It is 'only' a iptables problem, I think.
Does anybody know which rule I must setup?

Some infos about my net:

192.168.200.0 / 24 --> LAN
192.168.200.1 / 24 --> wl500g

192.168.201.0 / 24 --> pptp dial-in-net
192.168.201.1 / 24 --> pptp-server
192.168.201.2-3 / 24 --> pptp-clients

(sorry for my english)

Kind regards,

mmX