samba - Apr 2004 - HELP: Permissions in Samba 3.0.2

We are having difficulty setting permissions with Samba 3.0.2.  Whenever we
use the DOS attrib +r command to make a file read only (or through the file
properties) we get an "Access Denied" error for all users except the
owner.
This happens even though we've setup our smb.conf to allow Administrator
root access (smb.conf below), and the file is rwxrwxrwx.

Here is our smb.conf file:
-------------------------
[global]
        # seperate domain and username (e.g. domain+username)
        winbind separator = +

        # valid domain users range
        idmap uid = 10000-20000

        # valid domain group range
        idmap gid = 10000-20000

        # allow enumeration of winbind users and groups
        winbind enum users = yes
        winbind enum groups = yes
        winbind use default domain = yes
        admin users = Administrator

        # GENERAL SAMBA SETTINGS
        workgroup = DOMAIN1
        dns proxy = no
        log level = 1
        log file = /var/log/samba/%m.log
        netbios name = SMBSERV1
        load printers = yes
        server string = Samba App Server
        password server = *
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        os level = 20
        encrypt passwords = yes
        printcap name = /etc/printcap
        security = domain
        max log size = 50
        browsable = yes

        # disable opportunistic locking - to fix database issues
        oplocks = no
        level2 oplocks = no

[SMBNET]
        comment = Shared Drive
        path = /var/winshare
        valid users = @"DOMAIN1+Domain Users", @"DOMAIN1+Domain
Admins"
        read only = no
        public = no
        writable = yes
        printable = no
        nt acl support = yes


Thank you kindly,
Josh