samba-tng and access problems

[Michael.Scheinost at sinnerschrader.de]

Hi,

we want to use Samba on Linux as PDC for our NT machines.
I installed samba-tng 2.6 on Debian/GNU (kernel 2.2.17). I did it the way
it is described in various installation descriptions,
http://www.sambahq.de/hilfe.php3/tng0.html,
http://www.kneschke.de/projekte/samba_tng/faq/index.php3. I added the
machine and user accounts I want to use to the Linux users and additionally
added the NT users with samedit.
When I try to join the domain wit WinNt4.0, I always get the messege that
there is no machine account for this computer or that it is not accessible.
The log file log.samr writes:
>>
startfileent: unable to open file /usr/local/samba-tng/private/smbpasswd
unable to open sam password database.
startfileent: unable to open file /usr/local/samba-tng/private/smbpasswd
unable to open smb password database.
startfileent: unable to open file /usr/local/samba-tng/private/smbpasswd
add_smbfilepwd_entry: unable to open file.
Failed to add entry for user agnar$.
<<
Of course smbpasswd exists and is set to 600.

Could there be a dependency with the .map files?
Who can help?

TIA and greetings, michael