Samba PDC passdb backend configuration warning tdbsam. Was nun?

Hallo,

ich bin bei Installation von Ubuntu 7.10 / Samba PDC. Version: 3.0.26a

Hier ist mein smb.conf:
[global]
workgroup = DOMAIN
netbios name = LINUX
server string = linux (%h)
interfaces = eth0
obey pam restrictions = Yes
passdb backend = tdbsam guest
passwd program = /usr/bin/passwd %u
passwd chat = *Enter\snew\sUNIX\spassword:* %n\n *Retype\snew\sUNIX\spassword:* %n\n .
syslog = 0
log file = /var/log/samba/log.%m
max log size = 1000
name resolve order = wins lmhosts host bcast
logon path = \\192.168.1.2\profile\%U
logon drive = h:
domain logons = Yes
os level = 200
preferred master = Yes
domain master = Yes
wins support = Yes
panic action = /usr/share/samba/panic-action %d
profile acls = Yes
hide files = /?esktop.ini/ntuser.ini/NTUSER.*/?humbs.db/

[homes]
comment = Home Directories
read only = No
create mask = 0700
directory mask = 0700
browseable = No

[profile]
comment = Profildateien
path = /home/samba/profile/%U/
valid users = %U
read only = No
create mask = 0700
directory mask = 0700
browseable = No

[netlogon]
comment = Network Logon Service
path = /home/samba/netlogon
guest ok = Yes
share modes = No

wenn ich nun ein Benutzer in Samba eintrage
mit sudo smbpasswd -a benutzer
bzw. sudo smbpasswd -x benutzer

bekomme ich eine Warnung:
WARNING: Your 'passdb backend' configuration includes multiple backends. This
is deprecated since Samba 3.0.23. Please check WHATSNEW.txt or the section 'Passdb
Changes' from the ChangeNotes as part of the Samba HOWTO collection. Only the first
backend (tdbsam) is used. The rest is ignored.

Ich glaube das zu verstehen, was da steht, doch ich weiß nicht was ich damit machen soll.
Ideen? Tipps? Links?
Danke!!!