That's an invalid configuration. Disable one NIC and remove that cable on that nic.
I have 2 NIC on my PC (windows 2000). Both of them have consecutive IP address. I have connected them to a hub to which a router (linux box) also is connected.
My problem is one of them shows "A network cable is unplugged" even though it is connected properly. I have added the added the IPs in both teh pcs in hosts file.
However, if I plug the cable directly to the router's NIC, it works fine.