[Samba] Unable to use 'valid users' from Active Directory

[Reese,Richard Stephen]

I am able to return users and groups using wbinfo -g and -u. Samaba will
even allow users to connect that are in our domain. The problem exist
while trying to narrow down permissions to a share.

[public]
   comment = Public Stuff
   path = /home/
   public = yes
   read only = no
   valid users = @"UFAD\_IFAS-FRE-USERS_autoGS"

This does not work. It prompts the end user for a username/password but
it won't take anything. A share like the following does work but doesn't
bother asking the end user for credentials because the username/password
is already been entered to login to the AD domain.

[homes]
   comment = %U Home Directory
   browseable = no
   path = %H
   valid users = %U
   writable = yes
   create mode = 0664
   directory mode = 0775

I have also attached my smb.conf incase I missed something else.