Hello, I am having a problem when viewing some 720p HD YouTube videos in full screen mode. The video will start off fine, but then the video will start to develop an annoying audio lag after around 20 seconds (if the video has options for either 720p or 1080p, the 720p will lag and the 1080p will play fine). I know it isn't the video, because when it starts to lag, I can click on the progress bar to around where the video is currently at, and the video will refresh I guess, and the audio and video will be in sync again (for a little while at least). I am not really sure if this is a hardware or software problem. My MBP specs are in my signature, and has these graphics: Intel HD Graphics / NVIDIA GeForce GT 330M graphics processor with 256MB GDDR3 memory. I use Firefox 3.6.10 (and I also tested this with Safari). I also have all available updates for Snow Leopard and Adobe Flash. The weird thing is that this only occurs on certain (but a lot) of videos. Remember, it only lags when in 720p and in full screen. These videos will play fine in 720p full screen mode with zero audio lag: Sample Video 1 Sample Video 2 These videos will have an audio lag after around 20 seconds or so and viewed in 720p fulls screen: Sample Video 3 Sample Video 4 This has been bugging me for a while. Any one else experience the same problems and/or have a solution? Thanks.