Configuring Internal DNS as primary name server

I have installed and configured Microsoft Windows 2000 Active Directory native domain with Exchange 2000. The domain has an active directory integrated DNS and is working fine. I am able to browser resources inside my network. Exchange server is also able to send and receive mail to users inside the LAN. I register my domain name with register.com for two years.

I acquired a DSL from speakeasy.net with the agreement to have two static routable IP addresses and able to use their primary and secondary DNS servers for additional cost. I have a Lynksys DSL/Modem router/VPN configured to use one end the static routable ip address and on the other the non routable (10.10.10.1) ip address. It is working fine and all of my client (configured for DHCP) are able to get connection to the internet (used the Isps dns first and my own dns second) and able to browse the internal network as well.
My Exchange server since it is integrated with AD uses only the internal dns to logon and communicate. When I tried to use speakeasy's dns as first and my internal second, all of the services fail to start and causing all kinds of problem. I can not send and receive email to the world. I have tried to make the following change to make my dns serve as primary .
1. Changed the dns server sequence on register.com to have my name server as primary and speakeasy name server as secondary.
2. Let the people at speakeasy change their entry on A, MX and Glue record to reflect my name server as primary and their as secondary.
3. Add entry on my name server for a, mx for my mail server and made their mail server as a secondary.
4. Open port 52 and 53 for both protocols on my lynkysis router so that zone transfer between my server and speakeasy secondary name server.
After doing all this, I tried to use nslookup and check if I can resolve microsoft.com. The result is my name server does not know the address I was looking...

Any idea or advice on how I can make my name server working as a primary name server and let exchange server work its job?

Thanks in advance

Dereje