We are running OES11SP1 version for DNS/DHCP.
For some a records we see that no PTR record is created.

Normally if you create an a-record it should be automatically created right?

We saw the issue with doing a reverse DNS lookup with nslookup.

*** dns.x.x can't find xxxxxxx: Non-existent domain

I created some new a records today and then the PTR's are created.
Seems to be sometimes it is creating sometimes it isn't.

What can we do ? Why do we have this issue?