Whenever I try to watch a movie on youtube or something else that uses flash player, the video flashes green over the video. I've installed the latest player, but it doesn't seem to help.
I've seen this with Windows Media Player. What happens is the video is resized to stream better and it "inverts", turning green. A usual cause is screen resolution not set correctly. (usually too low, like 800 X 600 or even 1024 X 768). I hqaven't seen it with Flash Player or streaming Flash videos, but I'm guessing it has the same cause.
Also you might want to look into updating your video drivers.