[Samba] Domain authentification problem with LDAP

[Daniel Tousignant]

We use samba 3.0.13 and openldap 2.3.6
Members of the ldap group "Domain Admins" are working fine, but
members of the group "Domain Users" can not login to the domain,
and do not have access to the shares. Also, we are unable to join
a windows xp workstation to the domain.
Can anyone give me a hint where to start looking ... 

Thank you