I don't know much about how the changer works with the radio, but I'm guessing that maybe the radio can sense when a changer is attached; if it's not attached, it will only go into radio mode. Maybe your player isn't skipping, but it is actually cutting out sound. I don't think it's something wrong with your player per se, but if the sound is choppy, maybe there is a loose connection. I arrive at this conclusion, because sometimes your head unit switches to radio. I'm thinking that if the car shakes it enough, the changer disconnects for a split second, and the radio suddenly thinks there is no changer, so it switches to radio automatically. Just a guess, though.
