I am trying to play an HD (.mkv) movie with my div-x player and the video works perfectly fine when the setting for audio is off. However, the player refuses to play the video and audio when I turn the audio on. As far as I know I have the right audio codec, AC3filter , and I just recently installed the divx player. I'm running vista ultimate 32 service pack 2 if that helps. How can I fix this? Thanks in advance.