I wrote an earlier post that said when I edit a video with 60fps I can see only half the frames. I have since discovered that if I single step through the frames in reverse I get the frames skipped on the first pass, but it skips the frames I saw on the first pass. It doesn't happen when I just look at a couple of frames, but if I step through 4 or more the frames skipped in one direction show up in the other direction. Very strange behavior but it allows me to see and copy any frame.