Now for your question;
Never try to mix different formats in a project. As you are seeing, it creates problems, such as the jerky, repeating frames.
Try starting a new project, then bring in the 2nd video render it to a video file. If you are going to burn a dvd, then having the video files with different properties may produce better results. Of course when you get to the burn stage, you will have your video files that you created in the edting stage.
However I'm not sure how different the properties are. Are we talking different as in NTSC and PAL, or are they both at least the same there?
Ron P.
