Yes, I understand what you mean. At least I think I do - actually, others have referred to it as "run-through" rather than "skipping over," but I think we're talking about the same thing. If I realy do understand what you are saying it happens like this: the song plays for a very short time - maybe a second or so (if it plays at all) and then goes on to the next song and does the same thing again. Is that right?
Anyway, lots of people have had this problem, myself included. I'm away from home, where my other mac is, and so I haven't had a chance to try the "repair" that I referred to earlier, but I'm going to give it a try as soon as I can.
Also, I confess that I just got sick and tired of trying to fix the problem and today bought an iPod Nano.
Patrick