Reason I ask is ive visited some tgp post and when i click on videos to view they are all viewable. I just recently started using MPEG for testing a few days ago. I got the codec like 2 months ago but hadn't had time to try it out. I did a test and I was not able to play it until I upgraded my quicktime to the new version on their site. I also went to the microsoft site and downloaded the codec for media player. The the file extensions are .mp4 and they play after that. So since i havent seen any tgp's that are using .mp4 I beleive they are still on MPEG1.