Active Directory Integration: Group Member Attribute

This is my initial attempt to setup LDAP authentication for webMethods and obvoiously coming across issues:

I have a Active Directory (AD) group “+ADC UNIX” which I have mapped to the Administrator ACL successfully. However, unless I have the “Default Group” set to Administrator I am not able to get members of this group to access the admin console page. However, this obviously is not desirable, since I want the ACL mapping to dictate group privileges for users. There are other AD group who should not be getting Administrator privileges.

What am I missing? It seems “Group Member Attribute” is what is used to identify the membership. To me it looks like its not working. Any advice, anybody?

I have tried the following attributes in “Group Member Attribute”

Find below the LDAP Directory Settings and also server log at debug level 10 when attempting to login as nmathew who is part of “+ADC UNIX” group.
Directory URL: ldap://
Principal: nmathew
Credentials: ****