Domain Controller issues

I am in process of trying to remove a SBS 2003 server (ServerA) from my domain. I have successfully upgraded from Exchange 2003 on the SBS server to Exchange 2010 on a new server (Server B) running Server 2008 R2. My next step is to try to demote the SBS server. However it is the PDC. I had already made the new Exchange (Server B) a DC before adding Exchange 2010. DCDIAG passes fine on both the SBS Server (Server A) and the new server (Server B). Now here is my issue: My plan is to dcpromo another 2K8 R2 server (Server C) to be the PDC and to demote the SBS server. I want 2 DCs on the domain. The PDC to be the non exchange server (Server C)  and the exchange server (Server B) to just be my 2nd DC.
When I  try to run dcpromo on Server C, it fails. I went back to Server B (exchange) and ran the Best Practices Analyzer on it. I receive the following:
"Issue: The "DcByGuid" DNS service (SRV) resource record that advertises this server as an available domain controller in the domain and ensures correct replication is not registered. All domain controllers (but not RODCs) in the domain must register this record."
I followed the resolution procedure and the "DnsAvoidRegisteredRecords" parameter is not in Group Policy or the Registry.
I feel that this may be the cause as to why I cant add the new DC on Server C.
ANy help would be greatly apprciated...