Since the day i received my '12 uMBP, i've experienced this annoying problem with Youtube on Safari. As it loads, the grey buffer moves and it starts playing. Then after about 15secs, the grey buffer line disappears and the red playing line disappears too, but the movie keeps on playing for another 10 seconds then the video goes blank, like it is finished. This happens every time and for every video in youtube w safari. But it has no prob in Opera. Ive tried deleting cache, history but the problem keeps occurring. help?