Thanks. That is a very good explanation. My wife bought two micro SD cards whilst in the Philippines, strangely, one of them (so far) works perfectly! The one that failed could initially be read by the camera, as the images were visible on the LCD; however, when she next switched on she got the message clean card or format. The card was sent of for recovery, but turned out to be unreadable; they tell me that the controller on the card has failed - their program (and the one on my computer) reports 250 Mb of data which cannot be accessed. This last would be consistent with the images my wife said she had previously viewed on the card prior to failure.
I’ve got to accept that the images may never be recoverable and that the card they’re on is fake. What I’d really like to know is how to spot a fake! :cry: