I have been away on an extended trip and midway during the trip the camera started creating new sub-folders on my SD card. All the images were saved but they were saved to up to 7 sub-folders, ranging from 101 to 108... I first though it was a problem related to the custom settings. So, I checked my custom settings, U1 and U2. And, they were fine. I removed the card (San Disk Extreme Pro UHS-1) and replaced it with another of the same type. The problem went away. I, then, shot another 3000 images and the problem did not reappear. Has anyone else experienced this problem? Do you think it is a faulty card? Ken Rockwell thinks it is a firmware issue but I believe it is the card.