Over the holiday break, I had a similar problem, though it was likely my own fault. I took my SD card out of my camera and popped it in the EE. I was able (though slowly) to view the pictures in the Gallery. After unmounting it, though, and putting it back in my camera, the camera could no longer recognize the SD card. I put it back in the EE, and it said the card was blank. Luckily, I had backed up most of my pictures.

Regardless, it was an unwise sequence to follow...