MKV is not one of the media options that are categorized because it is not a sanctioned format (not like WMV, MPEG, etc.) Besides, MKV is a flexible container format which can store just about anything (H.264, DivX, MPEG, any sort of audio, even menus and subtitles) while WMV, MPEG is more or less complete formats so they know what to expect while with MKV's you really can not tell without checking t