Unix password sync

[Mego]

Hi!

My problem: I have to setup a Samba-Server and I want to syncronize the
smbpasswd File with the passwd File.
Here are my information about my system and smb.conf file:
My OS: SuSE Linux 6.3 (Kernel 2.2.13)
Samba: 2.0.6
some smb.conf Parameters:
encrypt passwords = Yes
passwd program = /usr/bin/passwd %u
unix password sync = Yes
passwd chat = "*New password*" %n\n "*New password (again)*" %n\n
"*Password changed*"

Now my problem: The syncronization doesn't work. If I'm logged in as a
user and  want to change the password
with the smbpasswd command, I get this error:
machine 127.0.0.1 rejected the password change: Error was: The specified
password is invalid.
But I know that the password is correct!

In the smb.log I is the following error:
[2000/03/21 15:00:13, 0] smbd/chgpasswd.c:check_oem_password(693)
  check_oem_password: incorrect password length (-878254492).

What is the oem_password?

Thank you for your help!
greetings
Mego