We have a ax150i with 8 drive (250GB each) currently running. I was looking to replace some of the drives with new ones. So I ordered new drives from DELL. The drives matched the ones currently in the ax150i, but will not be recognized by the system. Does anyone know if there is any deep format on the EMC drives which allow them to work and prevent other drives from being used? I ran Acronis Backup & Recovery 10 trying to find a hidden partition but this came up with nothing. Any ideas???