I was out shooting today with my 5D Mark II. After shooting about 200 images in RAW2 on my Transcend 16GB 133x CF card, the camera stops working in the middle of shooting and I get a message saying "Card not formatted. Format card with this camera". One, what causes something like this to happen? And two, are the images I shot prior to the error message gone? If not, how can I get them back? I put the CF card in my PC and I get a message saying that the card needs to be formatted there as well. Any help would be greatly appreciated. Thanks!