Been using Firefox for some years with no probs, and I view YouTube videos constantly. But recently been getting a left to right twitch on the YouTube screen, and it seem after I've viewed a video --- very weird! Don't get the same problem with Chrome, but I'd rather continue using Firefox. Can I fix this? I noticed on your introduction to this screen you state:- "Be descriptive. Saying “playing video on YouTube is always choppy” will help us understand the issue..." Do I have the same problem? Thanks