I just bought and downloaded Vegas Movie Studio Platinum 14 (Build 122). Upon importing my very first video, I'm noticing a strange flickering at the top of my preview video. I have tried adjusting multiple settings, including the preview ram, and the one checkbox that allows the preview area to optimize the video or whatever (which wasn't checked in the first place).
I know it's not a problem with the actual video itself, because when I play it back on my computer, it looks just fine.
Here is a video of the issue within Vegas: 
Computer info:
Windows 10 Pro (Version 1607) - Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz - 16 GB RAM - x64 based processor