[Samba] smpasswd

[rich]

Hi,
I have just installed samba-3.0.22 and copied my smb.conf across from my 
previous version on the same machine. With my previous version I never 
had to run smbpasswd -a username. It would do the authentication from 
/etc/passwd. ie when I added someone as a user with useradd they would 
automatically be able to mount samab shares. I am now having to add all 
my users with smbpasswd.
I didn't compile the previous version. Could anyone tell me what I need 
to do to allow authentication from /etc/passwd?

TIA,
Rich

[global]
        workgroup = WORKGROUP
        server string = BLA
        unix password sync = Yes
        log level = 2
        log file = /var/log/samba/samba.log.%m
        max log size = 50
        wins support = Yes
        invalid users = root bin web
        create mask = 0777
        directory mask = 0777
        hosts allow = 192.168.1. localhost

[homes]
        comment = Home Directories
        path = /userdata/home/%u
        read only = No
        guest ok = Yes
        browseable = No