[Samba] can't contact domain

[Eric Evans]

Hello everyone,

Once again I'm trying to set up our Samba server to operate as a PDC, now 
that I've verified that I have a clean install of the Samba 3 
software.  However there are some difficulties with this.  On my client 
machine when I try to set the domain name in the system control panel, I 
get an error message saying that the domain could not be contacted.  I've 
set up my client with the IP address of the Samba server as a WINS server 
in the network control panel.  I have a machine account for the client set 
up in the /etc/passwd & shadow and the smbpasswd.  I thought I had 
everything set up that I need, but it must be the case that I'm still 
overlooking something that is needed in order for the client to recognize 
the domain.  I'm not seeing any error messages appearing in my samba.log 
file.  Anyody have any suggestions for further things I could check to see 
why my PC can't see my domain?

Thanks very much,
Eric

PS,
Here's the smb.conf:

[global]
         socket address = 128.253.175.155
         socket options = TCP_NODELAY
         invalid users = bin daemon adm sync shutdown halt mail news uucp
         max log size = 100
         print command = /bin/lp -d%p %s; sleep 5; rm -f %s
         printer = 128_1
         printing = SYSV

         wins support = yes
         netbios name = pleiades
         workgroup = PLAB
         passdb backend = smbpasswd
         os level = 33
         preferred master = auto
         domain master = yes
         local master = yes
         security = user
         domain logons = yes
         logon drive = h:

         log file = /var/log/samba.log
         log level = 2
         max log size = 50
         debug timestamp = yes

[homes]
         browseable = no
         read only = no
         writeable = yes
         guest ok = no

[amanda2]
         path = /usersp/amanda2
         browseable = no
         read only = no
         writeable = yes
         guest ok = no
         valid users = amanda

[khoisan]
         path = /usersp/khoisan
         browseable = no
         read only = no
         writeable = yes
         guest ok = no
         valid users = amanda,eric

[nu]
         path = /users/Nu_Archive
         browseable = no
         read only = no
         writeable = yes
         guest ok = no
         valid users = amanda,johanna,eric,laura,andrea,nina,andrew,howell