external connections give error 619

[dave]

Hello,
    I've got a FreeBSD vpn server with mpd going behind a pf firewall/nat
setup. All works when internal machines connect, yet whenever i try to
connect from an external address that is outside my network i get an error
619 "The specified port is not connected." Googling shows that i should pass
both tcp port 1723 and gre traffic, this i do. My vpn box is 192.168.1.3,
server logs show the verification of the username/password and the atempt to
establish the connection, but then it fails, just goes down.
Any ideas?
Thanks.
Dave.