Using TFS public workspaces on Windows Server 2012

Hi, I've been trying to setup AX 2012 R2 to run against TFS 2010 in a shared AOS environment. I've followed the MS whitepaper, and it works as expected on Windows server 2008, but on When AX runs on Windows Server 2012 users not owning the workspace can check out items from TFS, but AX doesn't see the elements as checked out. The AOT still shows the check out menuitem, and the workspace owner also sees the check out menuitem even though TFS shows the item as checked out.

All the servers connect to the same TFS server.

Does anyone have a clue to why I get this behavior on Windows Server 2012?

Thanks

Brian