I just updated to Firefox 37. The video on YouTube is now doing this: https://dl.dropboxusercontent.com/u/4643460/theissue.PNG . I have to disable uBlock or reload the page a few times before it will load right. It happens with any videos. I have tried 0.8.8.2 up to the newest. I have even tested AdBlock Plus and have the same issue. I am thinking it is something to do with the MSE getting enabled in Firefox 37.