Consider the following scenario. You try to create a synchronization connection to a domain in Microsoft SharePoint Server 2010. The domain contains an organizational unit (OU) that has the same name as the domain. In this scenario, when you populate the containers in the tree control, the OU node cannot be expanded or selected. In this instance, the OU that has the same name as the domain cannot be synchronized.
To resolve this issue, apply the following updates:
2276342 Description of the SharePoint Server 2010 hotfix package (spswfe-x-none.msp, osrchwfe-x-none.msp): August 31, 2010
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.