A further point about cards…
From my own experience…
I once had a CF card which was apparently corrupt – couldnt get anything using imagerescue (Lexmarks own supplied software) and couldnt even subsequently format the card without it aborting with errors.
I thought all was lost until i had a notion and used a puffer brush to cleam out the edge connectors on the card.
Result? – card read straight away and i was able to format perfectly first time.