Now, I'm not the best at this stuff either, but I do know that some audio players will not play stuff that has been out on a DVD/CD by a computer. I found this when I downloaded some music to play in the car, and it worked on the computer and also in the car, but would not work on the stereo in the lounge.
Try listening to it in a variety of machines - it may be that the one you are using isn't compatible. You may end up sitting in the car to listen to your work!!