My drive can't read my DDS tape.
Please check the following.
Poor quality media, worn media or dirty tape drive heads. Insert a cleaning tape, then use brand new media as old media may contaminate the heads again. If long periods go by without the use of a cleaning tape, foreign material will build up on the heads and a cleaning tape may no longer be effective. In this case the drive will need to be returned to an Authorized Sony Service Center for cleaning.
Tape was written in a different drive. One of the drives may be incorrectly aligned - Try a back up and restore using the one drive, tape, backup application and operating system.
Incorrect SCSI configuration can also cause these types of problems, for best performance it is recommended to configure the tape drive with a dedicated SCSI controller.