Poweredge 2850 with DAT72 Hardware compression or even software compresion

Iam using the dat72 HP tapes and Iam using the Backup Exec ver 10 for Backup solution.Iam selcting the harware if not software compression in veritas but none of them happening.When i see the tape drive properties Iam unable to change the drive compression to true.I updated the tape drive driver also but still.Iam able to do backup upto 36GB but not 72GB. If selcting more than that the backup will be failed with the error in veritas.