[Samba] Username in "admin users" is not eq root

[Buozis, Martynas]

Hello

I am stuck. I want Administrator to be "admin user" for Samba share, but
I can't achieve that. This is a setup I have :

[global]
        workgroup = DOMAIN
        netbios name = TEST
        security = domain
        password server = *
        wins server = 192.168.202.7
        wins support = no
        name resolve order = wins bcast
        winbind use default domain = yes
        allow trusted domains = no
        idmap backend = idmap_rid:DOMAIN=100000-100000000
        idmap uid = 100000-100000000
        idmap gid = 100000-100000000
        template homedir = /export/home/%U
        template shell = /usr/bin/bash
        local master = no
        domain master = no
        preferred master = no
        dns proxy = no
        preserve case = yes
        short preserve case = yes
        deadtime = 15
        log file = /opt/local/samba/var/log.%m
        max log size = 512
        log level = 3
        create mode = 0644
        force create mode = 0400
        security mask = 0777
        directory mode = 0755
        force directory mode = 0500
        directory security mask = 0777
        admin users = administrator

Alas user administrator is always administrator. I can't make this
account to became root. In smbstatus line it always appears like 
" 6378   administrator  domain users  mbwin        (xxx.yyy.zzz.ttt)".
Where can be a problem ? What I am doing wrong ??? All files that are
created on a share are owned by administrator, no abilities to change
permissions for other files with different owner.

I tried to specify also DOMAIN\Administrator, but it is not working
either (and I didn't expect it to work as I have "use default domain"
on). 

I will appreciate any ideas.

Martynas