Thanks for that Ken. Ok, updated the SCSI controller driver and installed latest Sony driver. Still get the same error messages together with "The device, \Device\Tape0, has a bad block." in the Event Log. I have looked at Doc Ref: 2241684 but the errors for the Sense Keys I am getting are not listed. They are: "00 50 03".
NT Backup also fails to run successfully with the same errors.
Any other ideas? Thanks Tim.