Dynamic Update Linux Host

[briandesu]

Dynamic update fails for linux host(s), but works properly for all
Windoze hosts.

DDNS Server: BIND 9 - only allows the Active Directory domain
controller and DHCP server to update the zone.

DHCP Server: ISC DHCP 3 - configured to update A and PTR records for
all hosts.

The linux clients are receiving addresses and DHCP options properly,
but are not being updated dynamically in DNS.

I did RTFM, and have performed Google searches, but have had no
success.  TIA for all help.