DHCP AND 2 DOMAINS

Hi....

We have an existing NT Domain with one PDC that serves as
a DHCP and DNS. In the same subnet we introduced a w2k3
server as a new domain and acts as DHCP and DNS. The DHCP
scope of both the servers are distinct do not overlap.

The problem is that all pcs from both the domains now
obtain their addresses from the w2k3 server and not from
NT one.
The second issue that i noticed is that some pcs (XP/2000)
lose their connection to the w2k3 DHCP server once they
obtain an IP and get it back once I choose repair LAN
connection from My Network
Places. I noted that during this diconnectivity they
still can ping to the NT server.

Any help is appreciated