Now this is odd. It doesn't work with gpu acceleration on HD videos (no white square on left corner) in Safari and Firefox, and as expected, the Nvidia 330M doen't even kick in. However, it does work in Opera 10.5 on the Macbook pro, and in all browsers in my '09 20" iMac (9400M)! I already repaired permissions, uninstalled and reinstalled flash, and I can't get hardware acceleration in flash on the macbook pro! It reports version 10,1,81,3 in both Macbook and iMac. What gives? This is a proper video to try it: http://www.youtube.com/watch?v=-zvCUmeoHpw . If anyone with a 330M iMac has Flash 10.1 preview (gala) installed, please try it - select 720p and see if it gets a small white square on the left upper corner. Thanks.