When the SD card is inserted in the camera can you see any pictures from the card? Is there supposed to be anything on the card? When you last formatted the card did you use the camera or the Mac to format the card? If you right click on the card and click on "Get Info" what do you see regarding space used and free space?
When in the camera, I can see no pictures and if I press the display button it says "Folder contains no images". There should be no images, I cleared the card on my Mac. I used the camera for formatting last and when I right click it says "1.4MB available" but the Mac says "No Photos". When I open folders on the card, they are all empty.
It happened at first while I was using the camera. It was fine and then suddenly it said card is full, but when I started it was empty. I had taken 43 photos at the time. :-/ Hopefully it is the card and not the camera.
I think the problem is with the file format on SD card. I have 8 MR and 32 MB SD cards, formatted as FAT, the only option that works for them. I believe that this camera may require FAT16, FAT32, or ExFAT file format. I don't know why the SD cards won't support these different file formats, but all my attempts to format them other than FAT fail. Can someone confirm my finding?