Hi, I have noticed some issues with Flash player in Firefox. Videos playing in Flash player, flashes so that I see the background about once or twice a second unless I engage full screen. When I engage fullscreen and later go back, selecting fullscreen a second time shows a full screen blackbox with only audio. The only way to resolve the issue is to reload the web page. Sometimes going back from full screen makes the OS X stop light buttons in the upper left corner disapper. Thank you!