[Samba] well-known groups and i18n

[Andreas]

I'm confused with group mappings. I have a win2k pt_BR server in
native mode. After joining the domain (samba-3.0.7) and configuring
winbind, I have these standard groups:

# getent group
(...)
MYDOMAIN\Computadores do domínio:x:16777216:
MYDOMAIN\Controladores de domínio:x:16777217:
MYDOMAIN\Administradores de esquemas:x:16777218:MYDOMAIN\Administrador
MYDOMAIN\Administração de empresa:x:16777219:MYDOMAIN\Administrador
MYDOMAIN\Editores de certificados:x:16777220:
MYDOMAIN\Admins. do domínio:x:16777221:MYDOMAIN\Administrador
MYDOMAIN\Usuários do domínio:x:16777222:
MYDOMAIN\Convidados domínio:x:16777223:MYDOMAIN\Convidado
MYDOMAIN\Proprietários criadores de diretiva de grupo:x:16777224:MYDOMAIN\Administrador
MYDOMAIN\Servidores RAS e IAS:x:16777225:
MYDOMAIN\DnsAdmins:x:16777226:
MYDOMAIN\DnsUpdateProxy:x:16777227:
(...)

Note that the groups are in pt_BR, even the well-known ones. Example:
"Computadores do domínio" -> "Domain Computers"
"Usuários do domínio" -> "Domain users"

wbinfo -g gives this pt_BR list also.

Now, groupmap:
System Operators (S-1-5-32-549) -> -1
Domain Admins (S-1-5-21-3151312473-487480696-3918700472-512) -> -1
Domain Guests (S-1-5-21-3151312473-487480696-3918700472-514) -> -1
Replicators (S-1-5-32-552) -> -1
Guests (S-1-5-32-546) -> -1
Domain Users (S-1-5-21-3151312473-487480696-3918700472-513) -> -1
Power Users (S-1-5-32-547) -> -1
Admins. do domínio (S-1-5-21-3151312473-487480696-3918700472-1263) -> ntadmin
Print Operators (S-1-5-32-550) -> -1
Administrators (S-1-5-32-544) -> -1
Account Operators (S-1-5-32-548) -> -1
Backup Operators (S-1-5-32-551) -> -1
Users (S-1-5-32-545) -> -1

How do these two results relate to each other? I'm confused. Isn't "Usuários do domínio" a well-known
group which already has a gid (16777222)? What would happen to "Usuários do domínio" if I mapped 
"Domain Users" to, say, "users"?