So I started ripping and converting DVDs for my apple tv 2.0. I used Mac the Ripper and then Handbrake to convert to mp4. I have an imac 2.4 ghz, 24". I used the apple tv preset, turbo first pass, and changed audio quality bitrate to 160. I ran the Matrix Reloaded through the process, synced with apple tv, and it worked great. So I started the assembly line, ripping DVD's and then queing them in handbrake. Occassionally I would add mp4s to my itunes library and test them out, either by playing on imac or syncing with apple tv. Worked fine. But then I encountered a problem. I have probably 30 mp4 files sitting on my desktop that I encoded with handbrake and I am unable to import them into my itunes library. Also, when I double click one of these mp4 files to try to play it from the desktop I get the message "The Movie Could Not Be Opened" - "Invalid Sample description found in file." What happened? I am not doing anything different that I know of. Any suggestions. This is my first mac so maybe I am doing something obviously stupid. Any help would be appreciated. I have many hours invested in these encodes so I would love to not have to go through it again.