I hope someone can let me know how can I fix this. I convert mkv to apple TV using handbrak universal format. It is HD 720p. I have Apple TV first generation. I have itunes on my macbook, connect to time machines. If I try to stream the HD movie, it will play fine up to about 15 mins, then it will pause and re-buffer (the progress bar show up and stuck there for a few secs, and then play like 30 secs and then stuck there). If I sync this movie to the apple TV, it will play fine, no stuttering at all. Therefore, I don't think it is enconding problem. Also, the strange thing is if I convert a HD TV show.... the length of the show is less than an hour, Apple TV has no problem to stream it, no stuttering, no rebuffering. I try to connect the macbook using ethernet and it does not help, try restore the apple TV, try use a new itunes libaray with just one movie, all these does not help. It seems it is always around 15 mins into the movie and it will rebuffer.... is there anyway to work around this? I really do not want to sync the movie before I watch it! Please help! Thanks.