I was successful in downloading an earlier TWiT session that is an MP4 file. It works perfectly.... so there's nothing wrong with my bit torrent set up. It also happens that they mentioned doing another videocast using H dot 264 and the host said that it was still a bit quirky. So maybe this is an H.264 problem. I'd still like to get a little more info if you know where I should look for it. Note added after I wrote the above.... Voilà. It is now working. I hit the <open> button in Azureus. QT player opens right up and starts to play the file I wanted. When I shut down and try to open the file directly with QT I get the same "don't recognize file" message. Re-opening Azureus and starting from there again gives me the file playing as I wanted. So I'm not sure what's going on. Any clues would be appreciated. The H.264 format is awesome. The quality of the QT pcture even at "full screen" is better than my regular TV. If you haven't had the opportunity, try it yourself. You'll be impressed. John