SAMBA create masks

["Carl Wilhelm Soderstrom" <carls@agritech.com>]

        I need to set up a shared directory, via SAMBA (1.9.18, on RH5.1),
with group permissions set to do anything. so I want all new files to be
created with permission 770.
        I'm trying to do this with the 'create mask' parameter in the
appropriate share in smb.conf; and I can't seem to figure out how to get the
outcome I want. I think I've tried every mask value from 700 to 770, and
never get permission better than 760. 

this is what the smb.conf man page says:

create mask (S)                                               
    A synonym for this parameter is 'create mode'.            
                                                              
    When a file is created,  the  neccessary  permissions  are
    calculated according to the mapping from DOS modes to UNIX
    permissions, and the resulting UNIX mode is then  bit-wise
    'AND'ed  with  this  parameter.   This  parameter  may  be
    thought of as a bit-wise MASK for  the  UNIX  modes  of  a
    file.  Any  bit  *not*  set  here will be removed from the
    modes set on a file when it is created.                   
                                                              
    The default value of this parameter  removes  the  'group'
    and 'other' write and execute bits from the UNIX modes.   
                                                              
    Following this Samba will bit-wise 'OR' the UNIX mode cre-
    ated from this parameter with the value of the "force cre-
    ate mode" parameter which is set to 000 by default.       
                                                              
    For  Samba  1.9.17  and  above  this  parameter  no longer
    affects directory  modes.  See  the  parameter  'directory
    mode' for details.                                        
                                                              
    See  also  the  "force  create mode" parameter for forcing
    particular mode bits to be set on created files. 

this is rather confusing to me, at best...

here's the share in smb.conf:

# this is a replacement for the sys share on the old novell 3.11 server
[sys]                                                                  
   comment = common documents                                          
   path = /home/sys                                                    
   users = admin, betty                                                
   force group = sys                                                   
   create group = sys                                                  
   create mask = 770                                                   
   browseable = yes                                                    
   writeable = yes                                                     
   hide dot files = yes                                                


can anyone shed some light on the subject?

thanks!
Carl Soderstrom
System Administrator	307 Brighton Ave. 
Minnesota DHIA		Buffalo, MN	
carls@agritech.com	(612) 682-1091