[Samba] Valid users question

[Michael Andrewjeski]

Hi,

I've a question about the syntax of the valid users option. Any help is
greatly appreciated!

Here is the Background:

samba 3.0.4 
Linux as Domain Member 
Active Directory, not in Native Mode
Compiler opions: --with-winbind --with-pam --with-smbmount 

The goal is to authenticate via the Windows Domain and allow access via
Windows groups.

The syntax in my smb.conf looks like this:

valid users = DOMAIN\SOMEGROUP

However, it doesn't work no matter what. 

I can authenticate individual users thusly:

valid users = DOMAIN\SOMEUSER

I've read about the "@" "+" and "&"  syntax, but they only seem to
represent Unix & Nis groups. 

Is there another way to represent Windows groups? Or is my config the
culprit?
Here's the conf file:

 smb.conf:

[global]

# workgroup = NT-Domain-Name or Workgroup-Name
workgroup = DOMAIN

# WINS service
winbind uid = 10000-20000
winbind gid = 10000-20000
winbind enum users = yes
winbind enum groups = yes
wins server = XXX.XXX.XXX.XXX

password server = *

server string = SAMBA

log file = /var/log/samba/%m.log
max log size = 0
log level =  10

security = domain

auth methods = guest sam ntdomain



encrypt passwords = yes

local master = no

dns proxy = no

[SOMESHARE]
   comment = Some Share
   path = /d1/articles
   public = no
   writable = yes
   printable = no
   valid users = DOMAIN\SOMEGROUP