> One more question;)
> How can I set the PPTP client to be able to reach the WAN?
>
> My firewall rule for PPTP clients look like this:
>
> PPTP clients
> Proto	  Source		Port	Destination	 Port	 Frag
> *	  PPTP clients	*	*		 *

Is the subnet you entered on the PPTP setup page a part of the LAN subnet?
If not, there will be no NAT going on, and you won't be able to access the
Internet through PPTP. The PPTP daemon is intended to be used with LAN IP
addresses (m0n0wall will do proxy ARP).

- Manuel