I have downloaded some .mkv files to my AppleTv that has the aTVflash in installed. However, when I try to watch .mkv files, the picture freezes in different frames before the appleTV restarts.

What is happening?

How can I watch these files, or files with BluRay quality?

MKV files in resolutions over 480p are not supported on the AppleTV. The proper video codecs are installed by aTV Flash, but the AppleTV does not have the proper processing power to play the files.

720p HD formats in AVI or WMV are supported.