By the sound of it, I think your card is corrupt. My camera card did the same and in the end it seemed to be the problem - so I had to replace it. I would think the principal is the same. They suggested I use a different card reader to see if that is not the problem, perhaps you can try to use it on somebody elses machine or at the dealer. Please let us know if you have sorted it out as it would be quite interesting to know the outcome.
I sure will let you know. I can read my card and the card that came with the machine on my computer. Thanks, Colleta