I have a HP DAT72 USB external drive attached to a Windows 2000 Server running Backup Exec 10d. It's been running fine and I was able to use different brands of DAT72 media I had. One day it just started to refuse to label new media - but only for the Imation and Quantum DAT72 tapes. Backup Exec would say "CRC error" and the drive would blink yellow "clean drive" light. Strangely it labels/formats without a hitch for HP DAT72 and HP DDS-3 tapes I have. Almost feels like a conspiracy. :-) It does still write to existing media OK. I do run drive cleaning tape regularly.
Any idea on what to check?