PPTP issues including issues with routing

i have a win2k3 enterprise server. intially, i had only one NIC which was
acting as both the VPN termination point as well as the standard server NIC,
but i changed this to a two NIC setup.

anyways, the way it's set is as follows:

internet
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broadband router
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(int0)
firewall (int1)= = = = = = \VPN interface\
(int2) |
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/LAN interface/-----------win2k3 server

i've forwarded 1723 on the router to the VPN interface. the Win2k3's NIC's
are on separate subnets/vlans. while i know i can move the VPN interface to
the subnet/vlan that connects the router and the firewall, i rather not do
it this way. i want some protection afforded to the VPN server.

the firewall issues, i'll admit, were a bear, have been sorted out... so
there is no issue with the firewall anymore.

i'm followed the following two:

http://www.microsoft.com/technet/pro...on123121120120
http://support.microsoft.com/default...b;EN-US;323441

there are two things i need. first, i have an issue with routing. second i
need some clarification on my setup and how things work.

i understanding concepts will help me resolve my issue with routing.

first of all, what fields do i fill for the VPN interface? i take the
interface needs an IP address along with a subnet mask, so what do i do
about the default gateway and the dns servers? the first tutorial only
mentions the ip address as the subnet mask, so i'm confused.

second, i thought the VPN interface was inactive and only became active to
respond to VPN requests. so i'd assume it would only responds to VPN
requests, however, i can ping the interface. so what's where did i go
wrong?

as i've read, VPN traffic should flow in one interface, and out the other.
however, it doesn't seem to be doing this. so in otherwords, routing seems
to be broken. how do i fix this?

finally, i have problems accessing another system on the VPN interface
subnet. apparently, the addition of the new nic has taken over the route
for that subnet which is causing problems. i need to be able to override
this route, better yet drop the fact that the VPN NIC is the default gateway
for this subnet.