No sound? On your computer or stand alone DVD player? If the audio on the DVD is recorded in PCM, and your player is set to play audio out through "Bitstream", you wont get any audio. All you have to do in that case is go to settings on your player, find audio out, and choose "Bitstream". This is only relevant if you are using digital audio on your player, though.

My apologies for the problem, but I have only had the PCM issue myself. hopefully we can figure this out for you without too much hassle.