[Samba] create and manage groups

[Guido Lorenzutti]

I have a samba PDC 3.0.14a and is running as a PDC. My domain members 
are windows 2003.
I have several users and several unix groups. I want to create some 
domain groups and map them to the unix groups.

When i check my current groups i get this:

net rpc group list
Password:
System Operators
Replicators
Guests
Power Users
Print Operators
Administrators
Account Operators
Backup Operators
Users

But when i want to add a new group...

net rpc group add "SysAdmins"
Password:
add group failed: NT_STATUS_ACCESS_DENIED

grep root /etc/samba/smb.conf
    admin users = root

Any ideas?

Tnxs in advance.