2000 Server IP problems

I have recently setup a new 2000 server as a DC, WINS Server, DNS Server and DHCP Server. Everything was fine until I had a reccomendation to change my domain from name.local (since I won't be hosting a site) to name.com. Now my WINS server is defaulting to my T1 IP even though it is specified as my LAN (internal) IP everywhere I can think of. If I have my T1 connection disabled, everything is fine, but as soon as I enable it (T1) the IP reverts back to the T1 (external) IP. Along the same lines, sometimes when I enable both the LAN and IP connections, my T1 does not work properly until I disable my LAN connection. Is there a way to force these IP's or is there a setting/config that I should check to make sure everyhitng is as I think. Just to clarify, I was having the same problem with the T1 connection not working all the time with the name.local setup.