Delegation question

[Balder]

Just re read that message and it didn't make too much sense so will try again

as there is no full stop at the end of the following line
;                         NS ad.domain.com
it would end up looking like this
;domain.com       NS ad.domain.com.domain.com
if you put a full stop at the end of this line see below it should work
                         NS ad.domain.com.
ad                      A       192.168.0.3
you could also do this
                         NS ad
ad                      A       192.168.0.3