[Samba] problem with authentication of groups(users) on share directories

[SALOME Alexandre]

Hi ,
 
Today I have the following sharing  in "Samba version 2.2.12 for Solaris
2.9":
                [produto]
		    write cache size = 384000
                comment = AREA DE DADOS DE PRODUTO
                path = /usr/produto
                read only = No
                valid users = @produto

 
where exists the users cs02929 pertaining to the group @produto. And
everything work's well.
 
I installed the "Samba version 3.0.23b for Solaris 2.9" in same server and
the same sharing.
If I use the user cs02929 to access the share directory don't work, (it asks
for to user and password to me) but if
I put my user in share, work's:
                [produto]
		    write cache size = 384000
                comment = AREA DE DADOS DE PRODUTO
                path = /usr/produto
                read only = No
                valid users = @produto cs02929
 
 
How I make so that the samba recognizes the group? 
 
My global is:+++++++++++++++++++++++++++++++++++++++++++++++++++
                [global]
                workgroup = COMAU
                server string = servidor  %L
                comment = SAMBA %v
                security = SERVER
                password server =172.18.156.49, 172.18.156.50
                log level = 2
                log file = /etc/sfw/log/log.%m
                max log size = 5000
                wins server = 172.18.207.50
                nt acl support = No
                #
                encrypt passwords = Yes
                unix password sync = Yes
                update encrypted = Yes
                restrict anonymous = Yes
                #
                username map = /etc/smbusers
                invalid users = root @root @sys reboot desliga
                #
                create mask = 0777
                force create mode = 0777
                directory mask = 0777
                hosts allow = 172.18.150. 
                browseable = No
                hide dot files = Yes
                #
                +++++++++++++++++++++++++++++++++++++++++++++++++++++
 
Thanks
Alexandre Salomé