DNS Server unable to interpret format

I am in a hybrid NT/2000 network. Currently, things are working OK except I am receiving an error on my 2000 server – event source NETLOGON, and description of “Registration of the DNS record ‘[our domain] 600 IN A 10.1.1.25’ failed with the following error: DNS server unable to interpret format.”

Some of the details change (we receive a lot of these errors, to the point where I need to clear the event log nightly), referring to Default-First-Site-Name._sites.[domain], but the final messageis always the same – unable to interpret format.

Any ideas?