Sorry... I don't know too much about MKV's... Did you rip it off of a DVD into that format? If so search google for DVDShrink (Awesome DVD Burning/Ripping program.) If you must convert MKV to DVD(.vob files by the way) try using a video converter such was WinAVI(The best one I've found so far... my search still goes on though.) if it doesn't support MKV try searching Google for "MKV to VOB video conveter" If this didn't help maybe someone else can go into more detail.... Good luck, man!