Did you try different movies? One thing I could think of is if you have a movie where DTS audio is the default audio for the movie (kinda rare, haven't seen many like this). Some sound cards don't support DTS, so unless you go into the movies audio menu and change to Dolby 2.0 or 5.1, you won't get any sound.
Also, I'm assuming you have sound for other things? Can you play music and/or hear other sounds in Windows? Make sure you don't have your sound muted in Windows or something. If your computers audio is working in every other way, don't know why it wouldn't play a movie. I'm sure it has nothing to do with the firmware of your drive. Pop an audio CD into the drive, does it work?
You need to post more info about your hardware before anyone could tell if you could have some compatibility issue. What's your sound card? Again, does it work besides movies? Which shuttle board are you talking about? etc Go to control panel-->system-->hardware-->device manager. Do you see any devices sticking out with a yellow question mark or red x (this could indicate a device conflict, or lack of driver or corruption of the driver).