Gpo’s are replicated by two systems : AD replication (GPC, the GPO console) and file system replication (GPT contained in SYSVOL, the different components configured). It happens nevertheless that the AD replication goes badly, so we will have a difference between the GPC and the GPT.
One of the new features of Windows Server 2008 R2 is the Active Directory Recycle Bin. We can now “restore” a user account that has been deleted. However, this requires a functional Windows Server 2008R2 level.