Help configuring AT with XP and Crossover Cable

(Sorry, my last post was premature...)

I currently hook my Audiotron to a router using DHCP. It works great
accept that the router belongs to my company and the IT guys reset it a
lot.

What I'd like to do is to use a Crossover cable to a new PCI NIC card
and static IP to the AT. So, I'll have two NIC cards, one which connects
to my router and to the Internet, the second which connects to the AT via
the Crossover cable.

I run XP with SP2. Last night I tried this using the following:

AT:
IP - 10.00.00.04
Subnet Mask - 255.255.255.0
Gateway - left open

PC:
IP - 10.00.00.05
SM - 255.255.255.0
Gateway - open

I was able to view the ATs web page, but it couldn't connect because I had
no value for the Gateway I guess.

What values for the Gateway should be used?

Also, once I did this, I could no longer connect to the Internet with my
original config. I ended up pulling the second NIC out and resetting the
original NIC to get it to work again.

Has anyone else ever made this work in a similar config? My goal is to get
the AT off of the router, and a direct connect seemed a good way to go.

Any help or alternate ideas are appreciated.

Thanks,

-Tim