Private and public networks

I've just about finished playing with Vista RC1 and I have a couple of
questions.

I run a small home networking using an older dlink 704P router
connected to an RCA cable modem provided by Roadrunner. I have set up
all computers to use a workgroup called STUDY in XP.

Vista RC1 seems convinced I'm on a public network, even though I have
set up a private network. I suspect this is because it's having
problems communicating with the DHCP server in my router. The only
way I can get it to go into private network mode is to manually set
the gateway and ip address for the computer as if it were a static IP.

Even with this setting it begins with a public network and switches to
the private network after about 45 sec to a minute.

I have also noticed that each time I boot to Vista the workgroup name
is changed back to WORKGROUP and the Network ID still seems to think
I'm on a buisness network. I change these settings, reboot and they
go right back to what they were before.

Can anyone explain this or is it just an RC1 bug that "will be fixed
in the final version?"