Active Directory Groups Don't Work with Linked Server?

I mapped a login created with an Active Directory Group on server A to a login on server B through a linked server on server A and received a null login error when attempting to connect.

I changed the Active Directory Group login to an individual active directory login and the connection worked fine.

I saw someone post online somewhere that Active Directory Groups don't work with linked server by design--but I wanted to get confirmation on this. Can anyone confirm this, particularly someone from Microsoft?

This might be the dreaded "Double-hop" scenario. There's a great rundown by a Microsoft Protocols Engineer here:

http://blogs.msdn.com/sql_protocols/archive/2006/08/10/694657.aspx

That will get you started on learning why this is happening.