Like another reviewer on the 90-Minute 5 Pack item, I can verify that these tapes have too much drag in the mechanism. On my Nakamichi BX-300, they frequently stop during recording or playback. It's a tension problem, wherein a high end deck will purposefully stop advancing the tape to avoid breakage; basically, it thinks the tape is stuck. Cheapo decks that do not have this feature may work fine with these tapes. I've had no problem with other, commercially available cassettes on this deck.