Domain member server doesn't show group list from domain

[PFilter]

I have 2 eBoxes setup; one is a PDC with groups and users defined.
The other is a file server configured as a domain member to the above PDC.
Here is the [global] from smb.conf on the fileserver:

[global]
 unix charset = LOCALE
 workgroup = bluedragon
 security = domain
 netbios name = fileserver
 server string = bds.com fileserver
 enable privileges = yes
 interfaces = eth0,lo
 bind interfaces only = Yes
 passdb backend = ldapsam:ldapi://%2fvar%2frun%2fslapd%2fldapi
 log level = 1
 syslog = 0
 log file = /var/log/samba/%m
 max log size = 50
 smb ports = 137 138 139 445
 name resolve order = wins bcast hosts
 time server = Yes
 printcap name = CUPS
 wins support = Yes
 dns proxy = Yes
 ldap suffix = dc=ebox
 ldap machine suffix = ou=Computers
 ldap user suffix =  ou=Users
 ldap group suffix =  ou=Groups
 ldap idmap suffix = ou=Idmap
 ldap admin dn = cn=admin,dc=ebox
 map acl inherit = Yes
 printing = cups





You may notice I have added "security = domain" in the smb.conf file. this was required in order to change
Server role: ROLE_SERVER_STANDALONE
into
Server role: ROLE_DOMAIN_MEMBER

Now, I have restarted samba on both the PDC and the file server.
When I create shares on the file server, and try to add access controls, there are no groups to pick from in the list.
I can pick users, and my local user is listed, but no domain users.