I need only certain parts of a video, so I removed many sections, some of them very short.  I set it to music and the playback looked good.  After saving the video and watching it again, I noticed that in many of the places where I made edits, some frames were somehow reintroduced into the playback.  The final outcome is jarring as throughout the movie there are flashes of different scenes.

Can this be fixed?  How?