I have the mid-2010 MBP 15" notebook running Snow Leopard. Earlier today I was able to play videos on Youtube. Now I can't. I only get a black box without play/pause toggle controls when cursor is moved. The only significant change was an update Apple pushed for Java today. I can play videos on Hulu and other flash-based video sites. The video doesn't work on Safari, Google Chrome, or Firefox. I provided a screenshot below if it helps. Thanks again!