samba - Apr 2013 - cannot add a linux as member to a PDC with linux

I had some linux boxes running Samba 3.5,3.6 x32 in my Domain running Samba
3.5.x, all are Centos 5.x.

My current boxes doesn't have issue, I can browse all of them in the
network without issue.

Just my PDC is x64, the other are x32.

I manage all my servers with LDAP, my servers can contact ldap and get
users, groups without issue.

Now, I try to add a new server running Centos 5 but x64 arch, I follow my
instructions to add this machine to my domain, setup ldap, authentification
is working I can query groups and users from LDAP, setup samba and try to
run the net join -S MYPDC -U DomainAdmin

But the command return:

cannot join as standalone machine

My config is this one:

[global]
        workgroup = MYDOMAIN
        server string = x64 Server
        netbios name = my-server64
        hosts allow = 192.168. 127.
        hosts deny = 0.0.0.0
        smb ports = 139 445
# passwd backend
        encrypt passwords = yes
#        enable privileges = yes
        password server = MYPDCHOSTNAME
#       security = DOMAIN

# Log options
        log level = 1
        log file = /var/log/samba/%m.log
        max log size = 500
        syslog = 1

# Name resolution
#        name resolve order = wins bcast hosts lmhost

# misc
        time server = No
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        use sendfile = yes

# Dos-Attribute
        Map to Guest = Bad User

# printers - configured to use CUPS and automatically load them
        load printers = No
        printcap name # printing         cups options         show add printer
wizard = No

        idmap config * : backend = ldap
        idmap config * : range = 10000-20000
# logon options
        logon script         logon path         logon path         logon home   
logon drive # setting up as domain controller
        username map = /etc/samba/smbusers
        preferred master = No
        wins support = No
        wins server = 192.168.2.24
        winbind nested groups = Yes
        winbind trusted domains only = No
        winbind use default domain = Yes
        winbind separator = +
        domain logons = No
        domain master = No
        local master = No
        unix charset = UTF-8
        case sensitive = No
        dns proxy = No
        write cache size = 65536

Some one could point me my issue?

I can query ldap for users, not using winbind.

My other server is equal but x32.

LIving the dream...