gre, nat, and ipfilter 4

Hello,
I'm trying to set up vpn so that remote users can get to my systems.
I've got an ipfilter 4 gateway with a default block policy, when the
firewall rules are set to permit all the connections go through, load the
rules, and gre doesn't go out, the connection hangs at the verifying
username and password before timing out. Relevant rules are below.

ipf.rules
pass in quick on rl0 proto tcp from any to 192.168.0.5 port = 1723 keep
state
pass in quick on rl0 proto gre from any to 192.168.0.5 keep state

ipnat.rules
map rl0 192.168.0.0/24 -> 0/32 proxy port 1723 pptp/tcp
rdr rl0 0.0.0.0/0 port 1723 -> 192.168.0.5 port 1723 tcp
rdr rl0 0.0.0.0/0 -> 192.168.0.5 gre

I've tried it with the map pptp line commented out and not neither works.
Any help appreciated.
Thanks.
Dave.