The oPlayer HD, why everytime when play RMVB movie, it will only has sound for a few seconds, then the sound gone, no more sound, later I tried to slide the time frame bar, the sound come back and starting to out-sync with the video, but also gone after a few seconds. Does anyone know which player is the best for playing RMVB movie, wihtout lag ot out-of-sync for the video and audio??