Fast repeats/flashes video clip So I've been pulling the last bit of my few hairs out of my skull for half a day now trying to figure out why my rendered video is NOT smooth like it is in the preview. 
Demo: http://seodagger.com/wp-content/uploads/2016/08/1111-2222.avi 
It's like it loops each soft cut (in the video strip) a dozen times before it moves on. This does not happen when I play it in the editor, but happens every single time I render it. Any ideas?
Been following a bunch of "rendering tutorials" just to make sure I am not missing anything but I'm starting to go nuts :(
Codecs.

Prefaced with my usual “very difficult to diagnose from a distance.”

All codecs are not created equal, and are complex beasts when it comes to decoding. This is especially true for encoded files that could be subject to massive frame compression such as screen captures.

Best test is to render each source file long sequence into a  stills or AVI JPG format from within Blender prior to editing, and then edit the resultant output.

If this works, and if you are so inclined to learn about the dark alchemy of codecs, I could explain further if required.