here; http://forums.cnet.com/7723-7598_102-547324/cnet-tv-dropping-a-lot-of-frames-on-27-imac/
You may want to add your problems as there has been no comeback in that discussion yet.
Good luck.
Mark
I have a core2duo 2.4 ghz macbook with latest flash player version 11 and 256 megabytes of video ram. These specs should be enough to play 720p video but the video is choppy and studders. The video also toggles between 480 and 720 while playing and does this quite often. My internet speed is 15 to 23 megabits down and 1.8 megabits up which I think is more than enough for HD playback. Netflix with silverlight works fine at 720p and so does the TWIT network which uses flash. What works great is the REVISION3 network which uses HTML5 for HD playback and all other resolutions which my computer has no problem playing with just a little bit of the CPU being used when using HTML5. Why does CNET video toggle between standard and high definition all the time?

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