samba - Jan 2010 - Samba (problem with "password server = 192.168.0.20 192.168.0.30" line in smb.conf)

Hello, dear developers!

We have the several problems with interaction between our Linux and Windows
servers.

Description of problem:

There are three servers in our network:
 1). Red Hat Enterprise Linux 5.2 (64-bit) with shared folders for users of
network (192.168.0.10);
 2). Windows Server 2003 R2 (primary domain controller of AD) (192.168.0.20);
 3). Windows Server 2003 R2 (secondary domain controller of AD) (192.168.0.30);

 Configuration of /etc/samba/smb.conf-file:
--------------------------------------------------------------
[global]
 workgroup = AAA
 server string = srv-db
 netbios name = srv-db
 hosts allow = 192.168.0.
 security = server
 password server = 192.168.0.20 192.168.0.30
 encrypt passwords = yes
 smb passwd file = /etc/samba/smbpasswd
 username map = /etc/samba/smbusers
 socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
....
---------------------------------------------------------------
When both of Windows domain controllers work successfully Samba-service on
RHEL-server work good.
If 192.168.0.30 (second server in configuration-file) is failed - Samba-service
work good,
but when 192.168.0.20 (first server in configuration-file) is failed 
then the shared directories on RHEL-server will be unavailable for users.

There is information in Samba documentation that a "password server"
line may be with several servers names or ips.

Couldn't you help us with this problem.

Thanks very much.


                                                             Alex.