Problema com CUPS

Olá, estou montando um servidor de impressão e tenho que colocar a permissões para usuarios, usuarios comuns só podem imprimir e usuario admins e suporte pode gerenciar e cancelar os jobs. Na hora de autenticação do CUPS eu só consigo acessar com o usuario root, mas preciso fazer a autenticação com o admin e o suporte. Já tentei adicionar os usuarios ao grupo lpadmin e não du certo.

Aque está a minha configuração.

# Administrator user group...
SystemGroup lpadmin, admin,suporte
#SystemGroup lpadmin
AuthType Basic
#Require user @Sytem
#AuthClass Group
#Group admins
#User admin
#====================
#DefaultEncryption Never
#====================
# Only listen for connections from the local machine.
Port 631
Listen 192.168.6.2:631
Listen localhost:631
Listen /var/run/cups/cups.sock
# Show shared printers on the local network.
Browsing On
BrowseOrder allow,deny
BrowseAllow all
# Default authentication type, when authentication is required...
#DefaultAuthType Basic
DefaultAuthType Basic
AuthClass Group
#AuthGroupName admins
# Restrict access to the server...
<Location />
# Group admins
AuthType Basic
AuthGroupName admins
Allow from all
Order allow,deny
</Location>
# Restrict access to the admin pages...
<Location /admin>
AuthType Basic
AuthClass Group
Allow from all
Order allow,deny
</Location>
# Restrict access to configuration files...
<Location /admin/conf>
Allow from all
AuthType Default
Require user @SYSTEM
Order allow,deny
</Location>
# Set the default printer/job policies...
<Policy default>
# Job-related operations must be done by the owner or an administrator...
<Limit Send-Document Send-URI Hold-Job Release-Job Restart-Job Purge-Jobs Set-Job-Attributes Create-Job-Subscription Renew-Subscription Cancel-Subscription Get-Notifications Reprocess-Job Cancel-Current-Job Suspend-Current-Job Resume-Job CUPS-Move-Job>
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
# All administration operations require an administrator to authenticate...
<Limit CUPS-Add-Modify-Printer CUPS-Delete-Printer CUPS-Add-Modify-Class CUPS-Delete-Class CUPS-Set-Default>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# All printer operations require a printer operator to authenticate...
<Limit Pause-Printer Resume-Printer Enable-Printer Disable-Printer Pause-Printer-After-Current-Job Hold-New-Jobs Release-Held-New-Jobs Deactivate-Printer Activate-Printer Restart-Printer Shutdown-Printer Startup-Printer Promote-Job Schedule-Job-After CUPS-Accept-Jobs CUPS-Reject-Jobs>
AuthType Default
Require user @SYSTEM
Order deny,allow
</Limit>
# Only the owner or an administrator can cancel or authenticate a job...
<Limit Cancel-Job CUPS-Authenticate-Job>
Require user @OWNER @SYSTEM
Order deny,allow
</Limit>
<Limit All>
Order deny,allow
</Limit>
</Policy>
#
# End of "$Id: cupsd.conf.in 7199 2008-01-08 00:16:30Z mike $".
#

Tente tirar estas virgulas, acho que isso gera um erro de sintaxe, deixe apenas espaços separando os grupos.
SystemGroup lpadmin admin suporte

Ou mesmo você pode deixar apenas o grupo padrão (lpadmin) e adicionar os outros usuarios no grupo lpadmin

usermod -G lpadmin usuario

habilite o syslog para *.auth e abra um segundo terminal com tail -f /var/log/message ( ou seu arquivo de log)
Tente autenticar e veja o que acontece

Acredito que isso possa ser solucionado acrescentando os usuários na lista de printer admin no Samba "/etc/samba/smb.conf" .