Hi Karl,

I need some time digest your proposed solution. Here is what I have done :

1) Add following two lines to Connectors.xml.

<authorizationdomain domain="spn" name="SharePointNative"/>
<authorizationdomain domain="spad" name="SharePointActiveDirectory"/>

2) restart mcf

3) Go to "List Authority Connections" add/edit "Authorization domain:" to connections. ("SharePointNative" and "SharePointActiveDirectory") appears in pull down menu.

4) Issue a search with following parameters 

AuthenticatedUserDomain_0=spn
AuthenticatedUserDomain_1=spad

AuthenticatedUserName_0=ahmet@g-b
AuthenticatedUserName_1=ahmet@g-b.entp

Seem working for now. I will read more and ingest these stuff seems pretty confusing :)

Thanks for your help,
Ahmet