Converting / Promoting OD Master from Replica

Has anyone successfully switched a Replica to a OpenDirectory Master? It tried it three times with different Servers. The Replica changed to be an OD Master, but i can´t login with Workgroup Manager with user diradmin and Password. Login with admin works, showed me all Users and Groups, but can´t change any settings. su to diradmin in Terminal works, ID and Groups for diradmin seems right.