DNS Forwarder Problem

Ok. I'd pull my hair out over this one if I had any. We have internal Win2k DNS servers (AD integrated). We also have a caching only DNS server in our DMZ running BIND.

The internal servers run great and the DMZ server runs great.....until I turn on forwarding. Approximately 2 days after enabling forwarder and pointing to the DMZ server, CPU utilization reaches 100 percent on the DMZ Server.

I did a network capture on the windows server and discovered a s--- load of recursive lookups being forwarded to the DMZ server which I don't understand because the Win2k server is authoritative for those reverse lookup zones.

I have also tried disabling recursive lookups on the Win2k servers, but I still get the same result.....100 percent CPU utilization on the DMZ server. As soon as I disable forwarders on the Win2k servers, CPU utilization drops to less than 5% on the DMZ server.

I'm stumped. Any ideas on anything I can try to fix this would be greatly appreciated. Thanks in advance for any help!

John H.