Recently we made some major changes to our network infrastructure at one of our two "sites" served by the Active Directory domain. This site's DC is also the PDC Emulator. However, NT4 workstations located at the other site are dropping off the network as soon as we update their configuration information to reflect the new DNS settings, with Trust Relationsip Failed, event ID 3210. This originally was manifested in a NT4 server that would drop off the domain in this fashion, be rejoined, but would cause this same error just a matter of days later. Though the other site DC is the PDC emulator, the affected machine event logs list authentication with their site's DC as the point of failure. We have also recently run Windows Update on both DC's to get the latest security updates, but both DCs are at Service Pack 2. The NT4 machines are running Service Pack 6a.