Profile installation failed

I have been trying for about a month now to get device management working on my local network. When I try to enrol a workstation Safari downloads a file called ota_profile.mobileconfig and opens it in System Preferences. I then click through two dialog boxes relating to Device Enrolment. I then get a couple of dialog boxes relating to Remote Management. I click Continue on both of these then enter the user name and password (user is has administrator privileges).

I am then presented with a message:

Profile installation failed.

The profile “Remote Management (com.apple.config.server.mydomain.com.mdm)” could not be installed due to an unexpected error.

Within the Console app the following entry gets produced:

17/07/12 7:05:56.271 AM System Preferences: *** ERROR *** [CPInstallerUI:502] Profile installation (Remote Management (com.apple.config.server.mydomain.com.mdm)) (Checkin 'Authenticate' failed: 0 <InternalError:1>)

I have read as many other discussions relating to this issue and tried everything advised. I have erased and reinstalled system and sever software on my machines, made sure all necessary ports have been forwarded correctly, demote an Open Directory master to a stand-alone server, reset the Profile Manager database using wipeDB.sh... I don't know what else I can try.

CAN SOMEBODY PLEASE HELP!? It's driving me mad.

Any new insights, things to test, things to try. I really need to get to the bottom of this.