I took 2 images yesterday and about 30 more today on the same card. I closed the camera down as normal when I had finished shooting. Three hours later I decided I would run through the images to delete any I didn't want before downloading to the computer. The only image to show on the screen was the first one I had taken yesterday; I was unable to scroll through as normal. On turning the back button to the left it indicated that there was only one image on the card and this had a small green key on it, presumably indicating that it/the card? was locked. I downloaded to the computer and there was only the one image. I am unable to delete this image in the camera. Does anybody know what may be happening here and what may have happened to the rest of the images? I have not removed the card or altered any settings in the menu.