We can all speculate about the cause of Bernard's problem, card, camera, reader, computer. But Bernard's point is to have TWO CARDS in the camera writing simultaneously to both, instant backup. I agree, two cards failing in such a short time makes me want to look at a cause other than the card(s), but regardless, having a backup is important protection. I've said it many times, many ways, but there are two kinds of people, those who back up, and those who will lose data. With today's relatively inexpensive, large cards, especially something like a 128GB, the need to have extra space in the camera, as in overflow to a second card, is minimal.