Hello, all. I have an iMac G5. Running Leopard 10.5.2. It's working just swimmingly... except that it won't play back h264 video. I have the latest versions of both Quicktime and VLC. Each app handles the video files differently. Quicktime will give me this message: "The movie could not be opened. An invalid sample description was found in the movie." VLC will play the audio, but not the video. My computer can handle HD playback just fine (I watch most of my movies in 720p AVI files,) so that can't be the problem. This is just driving me insane. Does anyone have a solution for me? If this is in the wrong forum -- could a mod move it to the correct one, please?