The Netlogon service on a DC registers dynamic DNS records to advertise AD services.
The registration happens when Netlogon starts and every hour thereafter. If a DNS server doesn't support RFC 2136, dynamic updates may cause errors. If you manually enter the DNS records, use Regedt32 to turn off dynamic registration at:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Netlogon\Parameters
On the Edit menu, Add Value name UseDynamicDns, as a type REG_DWORD. Set the data value to 0.
Delete the %systemroot%\System32\Config\netlogon.dnb file and restart the computer.
NOTE: Make sure you manually register the records in %SystemRoot%\system32\config\netlogon.dns. See the link to DNS Records Registered by Windows 2000 Domain Controllers in tip 2720.