Can’t bind 10.6 Machines to 10.6 OD.

We upgraded our server from 10.5.8 to 10.6 and everything works OK except this. I always get a "wrong password" message when asked for the diradmin credentials. It often works if we configure the OD manually in Directory Utility and add it to the search path. We can then bind it with no problems. Anyone knows why it's not working ? Also How can we clear the a client machine config in regards to Kerberos and binding in general ? I'm using netrestore here and when I try to bind, I get a message that the record exists already when it does not.