DDNS Failed

Hi,

I'm trying allow DDNS for a W2K3 machine to register AD.

zone "hq.arkonnetworks.com" {
type master;
file "db.hq.arkonnetworks.com";
allow-update { key rndc-key; };
};

But I'm keep getting

0x0000232A RCODE_SERVER_FAILURE

I tried changing

allow-update { 192.168.22.0/24; };

but still fails. But all my Windows clients can do DDNS. DHCP is also on
the bind 9.2.3 box. May I ask what some tips please?

Regards,
Norman Zhang