My sd card was working fine yesterday, took loads of photos and was going thru them on the way home. Today when i went back to check my photos again my camera came up with 'card error'. Ive tried putting the sd card into a card reader connected to my laptop but it still isnt recognised, it doesnt show up at all. Both the card reader and the camera works fine with other sd cards. Any idea where the pictures have gone and how I can get them back?