I'm seeing this as well however the cause is easy to find: the DNS server is not Windows.
In short, the main DNS server is BIND 9 with all the windows stuff (_.msdsc, _tcp, DomainDnsZones, etc) has been handed off to the 2003 server (DC).
I have deliberately turned off dynamic updates as I don't want Windows machines corrupting my zone files.
How do I turn off dynamic updates on a XP box??
Current solution is to ignore the errors since everything else is working.