Why do my pictures have a black background when I copy them?

Memory Stick reads "File Error" in camera after saving a copy of pictures to computer?

• I put my SanDisk Memory Card into my computer to view my pictures and to copy just a hand full of them. Now when I put the memory stick back into my camera, the pictures I saved a copy of aren't there and come up as "file error". When I saved them to my computer I chose the option "open folder to view files" under Windows Explorer, and saved a copy of the ones I wanted from there. When I stick the memory stick back in my computer even afterwards, I see them. Why can't my camera read them anymore? Is there a way to fix this to get them back? All of the ones I didn't copy to my computer are still there?

• Answer:

  Did you mess with any of the pictures? (rotate?)