I'm backing up my DVD collection in order to watch it directly from my pc so far the first movie works great, great picture great sound (digital5.1) the second, which is Shrek 2 the picture is great but the sound does not come out in 5.1 digital. I have try backing it up with dvd shrink & dvd decyrpter and both copies no 5.1 digital sound, only analog were am i going wrong?