Update: It worked. See here for details.
The previous solution didn’t work, after all. I started getting “Memory card error”, “Card is not formatted”, and “Image can not be displayed” error messages again.
My new approach:
- update my firmware (I was still running 1.00, while the new version was 1.02);
- only connect the memory card to the computer through the camera’s USB option (as in, never plug the SD card directly into the computer)
- only format the card in-camera;
- never delete photos in-camera (only delete via in-camera formatting option)