I have several DVDs using DVD MF but after about 45 minutes the sound just disappears, it is all perfect until then it suddenly disappears. I have also tried using DVD MWS but it hasnt accepted any of my files, it either gets stuck at 50% on the third bit (after encoding menus) or before it even starts it comes up with error 80041c21 and starts again. Any help wuld be greatly appreciated.