Symptoms
When you try to perform a crawl overlap in Microsoft SharePoint Server 2010 or in Microsoft SharePoint Foundation 2010, you notice that the start addresses of the content source cannot take ownership of the host header sites.
Cause
This issue occurs because the crawl overlap does not work correctly in the Host Header mode.
Status
Microsoft
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.
has confirmed that this is a problem in the Microsoft products that are listed
in the "Applies to" section.