I am also having a problem like this. I have a video clip, a little over 3 minutes, a audio track, and I'm adding still shots using the overlay. The first time I was making the video I was 99% done and watching the preview and there was a quick blip or clip ghost. I tracked it down to what photo it was, deleted that photo and it still had the blip. I removed many photos in that area of the video and could not get rid of the blip. I got it done to finding the culprit, but it was now a thin blue line that I could not delete, or adjust to a larger time frame because when I click on this thin blue line it jumps over behind the other photos. I ended up starting all over, from square one. I am about 1/3 into the video and a text overlay (that would not work for me and I'm sure I deleted it)blipped in a preview of the work I had done. I have removed all the photos, and have watched the original video clip to see if the ghost image of the text shows up and yes, it does. I went back and found a blue line in the timeline, but once again I clicked on it and it disappeared to the very beginning of the video clip and I can not find it, it is hidden. I tried opening it up with the storyboard and it does not show up. Is this a normal occurrence? This is a big waste of my time and money, please advise how to deal with this problem.