Hi everybody! I have been using MKVtools to convert mkv-files to mp4/mv4 since i got my ATV2. The settings I have used is pass thru on the h264 video, and converted the sound to AAC 5.1. In the device setting drop list, I usually choose Apple TV unless I forget to... The difference seems to be that if I choose "Apple TV", the file format comes out as .m4v and if the setting is "General" it renders a .mp4 file. I have had no issues in playing these files on my ATV2 what so ever, but since the upgrade to 4.3 (4.2?) the other day I have encountered that my files will not play on the ATV2. It might work with some files if I play them from the start, but if I try to skip ahead it just freezes and won't play. Most files freeze at start though. Anyone who recognizes this behavior and/or have a solution?