A "Registration Conflicat:Error DB Config" message means that the phone's mac address is not present in the device table of the database.  I am not sure I have seen DB Conflict.  I thought it may be a message that occurs when there is a model conflict between the actual phone and the phone as configured in CUCM.  For example, you add the phone as a 7961 in CUCM when it is a 7962.  I did a quick test in my lab and the error was "Registration Rejected: Error Mismatch".

I could speculate on things like auto-registration enabled but the database publisher is offline or communication from the auto-reg subscriber to the publisher is broken.  Or a database sync issue since we are talking "db conflicts".

Is it possible you could give more context clues on the issues you are seeing (aside from the error message).  Maybe we can give a more exact answer.

HTH.

Regards,
Bill