Alright, here is the story: I encoded videos from our Mexico trip with QT 7.2 on my iMac G5 (OSX 10.4.10). The video was captured and cut in iMovieHD and then exported there with expert option to h.264, 320*240, 12fps, 32K audio. I can play the resulting video just fine on my Mac and also on several of my PC's with anywhere from Windows 2000 to Windows XP SP2. All with various QT versions (no older than 7 though). However, my parents in Germany, which just bought an iMac (Intel) a year ago cannot play the videos. They upgraded their OS to 10.4.11 and installed QT 7.4 and still were not able to play it. In the browser (I had embedded it in a website) they couldn't see it - just the famous "?" .... in Safari and Firefox). I had specifically chosen h.264 to encode, since I thought it was a substantial codec and any QT should be able to play it ..... especially on a Mac. Well, eventually I told them to install the 3ivx codec (because I thought it might help in decoding) and voila, now they can see it. Still, I found it odd that they had problems viewing it .... maybe one of you can help? I uploaded one of the videos here: http://www.chocolateriewanders.com/file_junction/mexico/vulkan.mov Thank you for reading .... Wilhelm PS. I did also encode videos straight from QT with the above mentioned settings (and yes, I can view them on four different computers here at home)