I have an HP11.11 with HP Dataprotector connected to an EMC Disk Library emulating IBM TD3 devices. The problem is that compression becomes disabled at first mount of a tape into the device. The drivers on the HP Host are atdd which should be fine. I know of the problem with stape drivers disabling compression. I've ruled out the EMC library and the HP host and wondering if there are any issues with Data Protector?