samba permission management

["Steve Garcia" <steve adzac com>]

A question for the samba folks reading the list...

I have configured samba 2.2.7 (on an RH 7.3 system).  I wish to create a
share whose access permissions are based upon the unix permissions of the
underlying directory.  That is, in this example access should be given only
to members of the unix group parents.

I created a unix group, parents with the command: /usr/sbin/groupadd parents
I edited /etc/group and changed the parents parameters to:
parents:x:505:jenny,steve
I created a directory and set its permissions and ownership on the samba
server with:
mkdir /www/parents
chgrp parents /www/parents
chmod 770 /www/parents

My created a share in smb.conf like this:
[parents]
comment = test folder for parents only
path = /www/parents
browseable = yes
readonly = no
create mask = 0660
force create mode = 0660
directory mask = 0770
force directory mode = 0770
force group = parents

>From the unix shell, everything behaves as expected.  The users steve and
jenny have read/write access to the directory.  Other users do not.

>From a win98 client, however, other users DO have read/write access to the
directory.

I can't see what I have done wrong.

Steve