I am trying to connect via my XP VPN client to a another site overseas, I
have configured my VPN settings to use PPTP.

When I try and connect it connects to the server but falls over when
verifying the username and password, returns an error 619. I have checked
the username and password and these are correct.

We currently use BM 3.8 for our firewall and we do use NAT.

Can anybody offer any suggestions?