KDC is stopped! DNS setup problems, Help needed!

I have concluded that I have problems setting up proper DNS Configuration on our department OS X 10.3 Server. I Hope someone could give me some clues or help me:

The labcomputers get their IP-adresses from a centralized DHCP server. In a IP range that is from 10.0.51.50 – 110.
– The DHCP network have DNS nameserver adress that i 10.0.50.1/2

1. I have given the server a fixed IP: 10.0.51.50
2. I have setup the server as a Open Directory Master
3. Configured the DNS to forward DNS request to the 10.0.50.1 DNS server
4. Setup users and homedirectorys and etc..
5. I have configured the Client-computers to access the 10.0.50.50 server for directory access and autentication.

– And I have added users in the workgroup manager to the ldap/127.xxxxxx network visiable node.

I still cant autenticate to the macserver…. and Open directory overview says that: KDC is stopped.