160/320 GB SDLT Extenal Drive always reformat the media

[Md. Khairul Alam Prodha_2]

We have just install 160/320 GB SDLT external on HP tc4100 Windows 2000 Advance Server SP3.

We have checked from HP L&TT then it shows OK.
HP 160/320 GB SDLT firmware ver V075.

We try to take backup from ntbackup then it is ok.

But when we try to restore from same tape then cartridge not recognised, even when we unload the tape and load it again it shows unrecognised media found.

Please help us.