Ed,

I'm haven't configured a cable modem myself, but from what I've read if you have one IP address (typical, unless you pay for another one) you usually share the connection through a broadband router over your existing LAN and using ICS. The cable modem connects directly into the router.

But if isn't your lock-up problem and your connection is working well, there's no reason to worry about it. If you can, you might want to experiment with disabling one of the NICs for a few days (don't uninstall it) to see if your lock-ups go away. If they do, you probably have a NIC driver conflict.