Hello, I am not technical, and I am not going to get into the Flash vs H.264 debate, but Apple says h.264 is better because it doesn't crash the system and doesn't turn the heat up and eat up cpu. I joined youtube h.264 html5 program, in all honesty h.264 is performing worse than flash on my core2dou macbook. Its early 2009(or late 2008) model, 10.6.4 and I installed the latest graphics acceleration upgrade. I usually get fans at 2001 rpm and 72-C on CPU(161.6 F) with flash running youtube h.264 videos I get fans at : 3200 rpm or more! heat: 76-80 C(168.8-176F) do I have an issue with my computer or is it the h.264 too much to handle? or maybe youtube html5 is not h.264 after all?