Error in /var/log/messages:

Jan 13 15:47:30 fp8 [NCPL]: client 10.11.x.xx#33746: updating zone 'da.dynamics.co.za/IN': update failed: not authoritative for update zone (NOTAUTH)
Jan 13 15:47:30 fp8 dhcpd: Unable to add forward map from server2.da.dynamics.co.za to 10.11.113.200: not authorized

Here's my setup as best as I can explain it:

I have DNS and DHCP setup on Server1 (OES2SP2)
Server1 is the designated primary for the zones that need to be updated

DNS and DHCP setup on Server2 (OES2SP1)
Server2 is a passive primary for the zones that need to be updated

The DNS zones are configured to "allow update: ANY"

Both DHCP servers are configured to do dynamics updates, in fact their configuration is identical.

Server1 updates DDNS successfully but Server2 gives the errors stated above

I configured TSIG keys successfully but got the same errors stating that Server2 is not authorised to update.

Any suggestions or advice would be greatly appreciated.