The problem is probably not noticable with the bare eye. I've had the problem too and putting in a new cable fixed it. Though, looking at the old cable I could see nothing wrong with it.
It is possible that the unit worked at first just because it hadn't been used yet. You see, using the player causes it to heat up, and the cable to expand. It is possible now that the cable got out of alignment one fraction of a mm, but just enough to become a problem.
Again, contact support. You're not alone in this. I've ordered six players and three of them showed this problem.