ICS with 2000 AND XP

I used to have DSL, which came with a modem/router combo unit. I switched to cable, and they provided only a simple modem. I've only got 2 computers, and want to setup ICS. Both computers HAD Win2k Pro, until my wife got a Zen Vision:M for Christmas, which is not compatible with Win2k. So, we installed WinXP Pro on her computer, and now ICS will not work. I've been through write-up after write-up looking for help, but I've haven't found any that address doing ICS with 2k AND XP. Both computers have 2 network cards (As, I have tried them both as the host), and I'm using a crossover cable to connect the two. Any ideas?

I'm sure it's something simple that I haven't seen mentioned previously. ATM the XP computer is not connected, as I would LIKE to use the 2kPro computer as the host, as it's seems to be more reliable, and rarely has any trouble, where as the XP computer, at least prior to the upgrade, has some video driver issues, that cause hard freezes sometimes, so when it freezes, and has to be rebooted, the other PC looses connection...