[Samba] user == Administrator doesn't work

[Vadim Vatlin]

User in group Domain Admins hasnt superuser (Administrator) privileges.

For the first:

shell> adduser poweruser
shell> pdbedit -a -u poweruser
shell> id poweruser
uid=1004(poweruser) gid=1005(poweruser) groups=1005(poweruser)

shell> net groupmap add rid=512 ntgroup="Domain Admins" unixgroup=poweruser type=d
shell> pdbedit -vL poweruser
Unix username:        poweruser
NT username:          
Account Flags:        [U          ]
User SID:             S-1-5-21-464898509-599635920-2875905535-1009
Primary Group SID:    S-1-5-21-464898509-599635920-2875905535-512
Full Name:            poweruser
Home Directory:       \\domain\poweruser
HomeDir Drive:        
Logon Script:         
Profile Path:         \\domain\poweruser\profile
Domain:               DOMAIN
Account desc:         
Workstations:         
Munged dial:          
Logon time:           0
Logoff time:          never
Kickoff time:         never
Password last set:    Wed, 24 Oct 2007 15:44:59 MSD 
Password can change:  Wed, 24 Oct 2007 15:44:59 MSD
Password must change: never
Last bad password   : 0
Bad password count  : 0
Logon hours         : FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF


shell> adduser plainuser
shell> pdbedit -a -u plainuser
shell> pdbedit -nL plainuser
[skip]
User SID:             S-1-5-21-464898509-599635920-2875905535-1010
Primary Group SID:    S-1-5-21-464898509-599635920-2875905535-513
[skip]

Now:
1) I login on share as "plainuser" and create folder "222".
2) logout.
3) Login as poweruser, and I cant remove folder "222"
 Permission denied.

Why???