Haltech007

I have been using VP for a couple of years now and it has always worked well. In the last few weeks though, my videos have these big black flashes in the final render where each video segment is pieced together. It has never done this before, and I cannot figure how to get rid of it. I have tried all of the different quality settings for MP4 output, but the SmartMax 60fps seems to have the least flashes. Any ideas what's going on with this? HERE is an example.