I have been successfully using my D7100 since April This week I had two strange events where the shutter was clicking but no images were being stored. Those images were never seen again. Turning the camera off/on restored the ability to record images.
It seems like when the buffer fills (which was possible) that the camera is ceasing to recover? I was in the midst of shooting race finishers - bursts of 2-5 images. After a minimium of 10 minutes I resumed shooting and shot perhaps 30 images of the start of the next race - none of which were stored. Five minutes later when I noticed the problem I could not store a single image - until I powered the camera off/on.
I am using a 32 GB San Disk Extreme, freshly formatted in slot one - slot 2 empty. I have taken easily 2000 images on this card - formatting after each shoot - without a problem. I was using CH and CL settings.