Disconnected Network on Domain

We have been having network issues with Vista at my company that parrallel
many of the "Network Location" issues posted in this group.

When computers are joined to my domain, they work fine most of the time.
However, sometimes they will go to the "Local Access Only" state. They have
lost a DHCP number and are now assigned the 169 address. A Reboot causes
the machine to come back. However, simply repairing the connection does not.

If we take the machine and remove it from the domain, the issue Stops. We
are thinking that this is due to Vista turning off the network location
awareness when on the domain.

Does anyone have any thought on why a domain computer would simply decide it
has local connectivity only? These are not wireless, the connection is good,
and there is not a reason to loose connection I can see.

Thanks!

Kirk