Veritas Backup Exec on SCSI Drives

We are researching the use of Veritas Backup Exec on NT Workstation 4.0 using a SCSI Backup device (Sony SDT 9000) with Veritas BackupExec for Desktop on a Mylex DAC960 RAID 5 SCSI interface card. NT sees the tape drive but when we try to see the tape drive in the Veritas product the tape drive does not appear to be recognized by the software. Has anybody else experienced this type of problem with Veritas?