unix password sync problems!

[Glen GIBB]

I have been trying for hours to get the unix password sync going properly
with Samba 1.9.18p4 running on FreeBSD 2.2.5

I have compiled Samba with the ALLOW_CHANGE_PASSWORD option enabled.
I created the smbpasswd file as ENCRYPTION.txt states, and can set
passwords as root.

However, when a user tries changing their password, it doesn't work.
The error reported is:
/usr/local/samba/bin/smbpasswd: machine 127.0.0.1 rejected the password
change: Error was: code -1.

The user's unix password is actually changed, but their SMB password
isn't.

The following password related lines are set in the smb.conf file:

   unix password sync = True
   passwd program = /usr/bin/passwd %u 
   passwd chat = *Changing*for* .  *New*password* %n\n *password* %n\n 
*done*

The last few lines of the log file (debug level = 100, compiled with
DEBUG_PASSWORD enabled) are:
pty: opened /dev/ptyp7
Dochild for user grg (uid=0,gid=0)
chatbuf=[*Changing*for*] responsebuf=[Changing local password for grg.
]
sendbuf=[.]
chatbuf=[*New*password*] responsebuf=[New password:]
sendbuf=[222222
]
chatbuf=[*password*] responsebuf=[
Retype new password:]
sendbuf=[222222
]
chatbuf=[*done*] responsebuf=[
passwd: updating the database...
passwd: done]
sendbuf=[.]
chatbuf=[.] responsebuf=[
passwd: updating the database...
passwd: done]


Hopefully, someone out there has encountered this same problem, and can
tell me what I'm doing wrong.

Thanks in Advance
Glen Gibb