2 NICs on internal network

I have a netgear firewall protecting my overall network which assigns 192.168.0.x addresses to two servers one linux the other NT4.0(SBS4.5).

What I want to do is to put 2 nic’s in both these machines and pass that traffic through a firewall on each machine. I can do it OK with the Linux machine but the NT machine will not let me activate the firewall on MS Proxy 2.0.

My internal/internal IP range is 10.0.0 – what am I doing wrong?

Thanks in advance.

KP