You didnt really specify if the computers were sharing a cable modem or if they each have there own. If both computers are in the same LAN and share a cable modem my suggestion would be much different than the VPN or firewall route.

I have added IPX/SPX protocol to both machines and disabled file and print sharing over IP for security purposes. If this is your situation, I would be happy to explain this further.

-Doug
(Mk2-12G-Blue)