co.za domain problem

[rotto]

Hi,
We have a domain example.co.za and we have a windows 2003 server.
On the server we setup forward and reverse DNS zones for example.co.za
In the DNS there is 2 NS records, ns1.example.co.za and ns2.example.co.za

Problem is when we try to point the domain to the server. We point it to ns1.example.co.za and ns2.example.co.za

The reply from uniform say: Error: No NS record found for ww23443.some-server.com
Now, why would they pick up our server as ww23443.some-server.com?
What can i do to resolve this problem?

Thanks