Can´t start Directory Bind on OpenDirectory Server

Hello folks - I´ve a problem to start the directory bind in the serveradmin. I just want to connect my mac clients to the existent Open Directory, but it didn´t work. The OD master runs on an xserve 10.4.11 including fileservice. The other xserve is configured as OD replic and Keriomail. I want a single user login for all services, and most things are working fine (mediawiki, mail, print,file etc.) but not the client directory binding... I can configure the OD in the dirctory access utility, but if I restart the client, I can´t login with an user that´s configured on the server. After checking all the configurations on the server and reading logs i have seen that the directory bind in server admin doesn´t work. If I try to turn it on, it´s unchecked after saving. I can´t delete the OD and setup a new one, because to many service are allready in use from more then 80 employees anyone an idea? thanksfully