Using Kerberos with OSXS services

I am trying to set up my xserve (10.3.3) to use our corporate Kerberos server. I can get accounts to authenticate fine from a console login, but services such as ssh, Samba and AFP do not use the Kerb authentication. I have set up a local account for each user and the Kerb password works for login, but the local password that I assigned also works (I tried to use an asterisk as mentioned elsewhere to disable local account logins but that ended up just being the local password ). So I actually have two problems: one is getting the services to use Kerb authentication and the other is disabling the password for the local account. Anyone know how I can get this working?