It is possible that the center of the X-frame of the HDD tray is slightly bowed which will cause the hard drive to warp when secured with screws. If warped, a head crash may occur that can destroy the drive. Only SATA (Serial ATA) drives are affected - PATA drives don’t have this issue. SATA drives are identifiable by a flat, X-shaped Mylar insulator between the drive and the tray - see the photo. Also affected are trays used for replacement/swapping purposes on the E836xA/B and N5230A models. This issue does not affect the PNA-X series.