I'm new to this so I don't really know all the ins and outs, obviously! You helped me the other day when I wanted to set the time for multiple still images by showing me control D. I drag any number of stills to the timeline hit control D and type in let's say 400. I did this for several sections of the piece. When I went back over it to sync up the audio I zoomed in and saw that these grey bars were between frames. But some of the sections I brought in were fine, not affected like this. There were some I looked at later that had several of the grey spacers (up to 5 in one area). I got rid of them before I thought to screengrab this. The images are all jpgs exported from Keynote files all created within the last several days, exported one after the other so I don't see any issue with wildly different files etc. I'm not sure what a gap clip is. The time of the spacer was .01, so yes 1 frame. The frame rate is 29.97.