domain level authentication?

[mjo]

I'm trying to set up a samba server, such that 60 or so win 98 users can log
into the linux box and be plopped into their respective home directories on it.
 I don't want them to be promted for passwords, I want the PDC, an NT box, to
take care that in such a wy that I do not need a smbpasswd file. I know almost
nothing about NT, but the server running works just fine, and will let people
authenticate into samba as long as I set it up authenticating against a
smbpasswd file.

Here is the relevant part of the smb.conf file I'm using:
[global]
        netbios name = MYNBNAME
        workgroup = MYDOMAIN
        server string = Samba %v on (%L)
        log level= 1
        max log size = 1000
        encrypt passwords = yes
        security = domain
 
[homes]
        brosweable = yes
        map archive = yes
              

[data]
        path = /data
        comment = data drive
        volume = Data-Drive
        writeable = yes


MYNBNAME is listed in the NT box's server manager.
I shut down samba, type
smbpasswd -j MYDOMAIN -r MYPDC
        
Here is the error I get:

cli_net_req_chal: Error NT_STATUS_NOT_SUPPORTED
cli_nt_setup_creds: request challenge failed
modify_trust_password: unable to setup the PDC credentials to machine MYPDC.
Error was : NT_STATUS_NOT_SUPPORTED. 2001/03/13 11:03:37 :
change_trust_account_password: Failed to change password for domain MYDOMAIN.
Unable to join domain MYDOMAIN.        

I have also tried setting setting sercurity=server.

Any thoughts?  Thanks!
-Mjo