Hi, I've noticed lately that whenever I start watching a youtube video on my early 2011 Macbook Pro 13inch i5 with 8gb of ram it starts the fans going. I only have Google Chrome, Skype, and Mail running. It usually never does this but recently it has starting doing it. It stops if I exit out of the youtube video tab or if I pause the video. Btw, I'm running OS X Mountain Lion.