DHCP running on Windows, DNS on Novell OES -> No PTR Updates

Due to other external constrains, we are running DNS Services on our Novell OES Server and DHCP on an older Microsoft Windows Server.
The challenge is to integrate both and make them work together so that the DHCP Leases and their DNS Pointers get correctly registered, updated and deleted at the DNS Server.
The MS DHCP Service hosted in the Windows Server is already configured to "Enable DNS dynamic updates" and "Always dynamically update DNS A and PTR records".
But our conclusion is that the Novell OES Server is not capturing,accepting and executing those updates.

Any thoughts which could help us solve this problem?

Thanks!