I just upgraded from a fully operational 3.0.0 Samba configuration to
the new 3.0.9 version.  In each case I use exactly the same smb.conf
file.

When smbclient connections (on the localhost or remotely) are attempted,
then the smbpasswd entry from that attempted user is reset to
the 32 X's for both fields between the colons.

This prevents all logins to 3.0.9 since each login account is
disabled as it is attempted (both root and non-root accounts).
Note that both smbpasswd and secrets.tdb are updated.

Reverting back to 3.0.0 correctly restored the correct behavior.

For reference, below is my smb.conf file 

Thanks for your efforts and support,

Scott Nelson
nelson18@llnl.gov

----
# This is the main Samba configuration file. You should read the
# smb.conf(5) manual page in order to understand the options listed
# here. Samba has a huge number of configurable options (perhaps too
# many!) most of which are not shown in this example
#
# Any line which starts with a ; (semi-colon) or a # (hash) 
# is a comment and is ignored. In this example we will use a #
# for commentry and a ; for parts of the config file that you
# may wish to enable
#
# NOTE: Whenever you modify this file you should run the command "testparm"
# to check that you have not many any basic syntactic errors. 
#
#======================= Global Settings =====================================
[global]

# workgroup = NT-Domain-Name or Workgroup-Name
   workgroup = www-dsed

# server string is the equivalent of the NT Description field
   server string = Samba Server

# This option is important for security. It allows you to restrict
# connections to machines which are on your local network. The
# following example restricts access to two C class networks and
# the "loopback" interface. For more examples of the syntax see
# the smb.conf
hosts allow = 127.0.0.1, 0.0.0.0, 128.115.97., 128.115.101., 128.115.177.,
128.115.15., 128.115.142., 128.115.168., 134.9.156., 199.120.46.144,
128.115.159., 128.115.160., 128.115.160.87, 128.115.161.113, 128.115.161.9,
134.9.156.38, luxor.llnl.gov, econt4.llnl.gov, econt5.llnl.gov,
canopus.llnl.gov, azquix.llnl.gov, solarium.llnl.gov, duality.llnl.gov,
eta-ii-mech.llnl.gov, suicide-machine.llnl.gov, localhost, fits.llnl.gov
#hosts allow = 128. 134. 0. 127.

# If you want to automatically load your printer list rather
# than setting them up individually then you'll need this
   load printers = no

# you may wish to override the location of the printcap file
   printcap name = /etc/printcap

# on SystemV system setting printcap name to lpstat should allow
# you to automatically obtain a printer list from the SystemV spool
# system
   printcap name = lpstat

# It should not be necessary to specify the print system type unless
# it is non-standard. Currently supported print systems include:
# bsd, sysv, plp, lprng, aix, hpux, qnx
   printing = lprng

# Uncomment this if you want a guest account, you must add this to /etc/passwd
# otherwise the user "nobody" is used
;  guest account = pcguest
  guest account = nobody

# this tells Samba to use a separate log file for each machine
# that connects
   log file = /usr/local/samba/var/log.%m

# Put a capping on the size of the log files (in Kb).
   max log size = 5000

# Security mode. Most people will want user level security. See
# security_level.txt for details.
   security = user
# Use password server option only with security = server
;   password server = <NT-Server-Name>

# Password Level allows matching of _n_ characters of the password for
# all combinations of upper and lower case.
  password level = 12

# You may wish to use password encryption. Please read
# ENCRYPTION.txt, Win95.txt and WinNT.txt in the Samba documentation.
# Do not enable this option unless you have read those documents
  encrypt passwords = yes

  passdb backend = smbpasswd 
  
  
# Unix users can map to different SMB User names
;  username map = /etc/smbusers

# Using the following line enables you to customise your configuration
# on a per machine basis. The %m gets replaced with the netbios name
# of the machine that is connecting
;   include = /usr/local/samba/lib/smb.conf.%m

# Most people will find that this option gives better performance.
# See speed.txt and the manual pages for details
   socket options = TCP_NODELAY 

# Configure Samba to use multiple interfaces
# If you have multiple network interfaces then you must list them
# here. See the man page for details.
;   interfaces = 192.168.12.2/24 192.168.13.2/24 

# Configure remote browse list synchronisation here
#  request announcement to, or browse list sync from:
#	a specific host or from / to a whole subnet (see below)
;   remote browse sync = 192.168.3.25 192.168.5.255
# Cause this host to announce itself to local subnets here
;   remote announce = 192.168.1.255 192.168.2.44
;   remote announce = 128.115.101.255

# Browser Control Options:
# set local master to no if you don't want Samba to become a master
# browser on your network. Otherwise the normal election rules apply
   local master = yes

# OS Level determines the precedence of this server in master browser
# elections. The default value should be reasonable
# default is 0 (the lowest).  Highest is 255
   os level = 0

# Domain Master specifies Samba to be the Domain Master Browser. This
# allows Samba to collate browse lists between subnets. Don't use this
# if you already have a Windows NT domain controller doing this job
;   domain master = yes 

# Preferred Master causes Samba to force a local browser election on startup
# and gives it a slightly higher chance of winning the election
;   preferred master = yes

# Use only if you have an NT server on your network that has been
# configured at install time to be a primary domain controller.
;   domain controller = <NT-Domain-Controller-SMBName>

# Enable this if you want Samba to be a domain logon server for 
# Windows95 workstations. 
;   domain logons = yes

# if you enable domain logons then you may want a per-machine or
# per user logon script
# run a specific logon batch file per workstation (machine)
;   logon script = %m.bat
# run a specific logon batch file per username
;   logon script = %U.bat

# Where to store roving profiles (only for Win95 and WinNT)
#        %L substitutes for this servers netbios name, %U is username
#        You must uncomment the [Profiles] share below
;   logon path = \\%L\Profiles\%U

# Windows Internet Name Serving Support Section:
# WINS Support - Tells the NMBD component of Samba to enable it's WINS Server
;   wins support = yes

# WINS Server - Tells the NMBD components of Samba to be a WINS Client
#	Note: Samba can be either a WINS Server, or a WINS Client, but NOT both
;   wins server = w.x.y.z

# WINS Proxy - Tells Samba to answer name resolution queries on
# behalf of a non WINS capable client, for this to work there must be
# at least one	WINS Server on the network. The default is NO.
;   wins proxy = yes

# DNS Proxy - tells Samba whether or not to try to resolve NetBIOS names
# via DNS nslookups. The built-in default for versions 1.9.17 is yes,
# this has been changed in version 1.9.18 to no.
   dns proxy = yes

# Case Preservation can be handy - system default is _no_
# NOTE: These can be set on a per share basis
;  preserve case = no
;  short preserve case = no
# Default case is normally upper case for all DOS files
;  default case = lower
# Be very careful with case sensitivity - it can break things!
;  case sensitive = no

; These are the settings required for IRIX password sync
;  passwd program = /usr/bin/passwd %u
;  passwd chat = *ew*password:* %n\n *e-enter*new*password:* %n\n
  
  
;   unix password sync = yes



;   nt acl support = no

name resolve order = hosts wins lmhosts bcast


#============================ Share Definitions ==============================
[homes]
   comment = Home Directories
   browseable = yes
   writable = yes
   guest ok = no

[eta2]
   comment = ETA2 Directories
   path = /nfs/torpedo/raid/eta2
   #
   # this is OK because it will defer to UNIX file permissions.
   read only = no
   hosts allow = 128.115.15., 128.115.101., 128.115.168., 134.9.156.,
128.115.161.113, 128.115.160.87

[jasper]
   comment = JASPER Directories
   path = /usr/people/jasper
   read only = no
   # 101 subnet and 15 subnet are in B543.  102 subnet is in B131 (Rosy Midtun)
   hosts allow = 128.115.101., 128.115.102., 128.115.15.

[hawkins]
   comment = Hawkins Directories
   valid users = hawkins
   path = /usr/people/hawkins
   writable = yes
   read only = no
   hosts allow = 128.115.101.
   create mask = 0775

[brown]
   comment = Brown Directories
   path = /usr/people/brown
   valid users = brown
   writable = yes
   read only = no
   hosts allow = 128.115.101.
   create mask = 0775