Steve
You are correct in my network description.
I did what you suggested....disabled DHCP in my router. I could not
get a DHCP lease.
I looked at the services in my XP box (the one that is doing the
sharing) and I only see dhcp client running. I don't see any other dhcp
service. It doesn't appear to me that ICS is providing dhcp addresses.
All my other PC's (wired ones) could still get out to the internet, but
the wireless boxes could not until I enabled DHCP in the router.