Hello, ever since the latest update on my Firefox account on my I-Mac whenever I try to watch videos on YouTube they start and you watch about 30 seconds of it then you get the white arrow circle. You have to click on the timeline just in front of where it stopped for the video to continue. The video will continue for about 20 seconds and then freeze again. Then you click in front of where it froze on the timeline and it will continue for another 20 seconds. I have stopped using my preferd web browser FireFox and now have to use Safari. Please help!