Layer Object Bug

I have seen other threads lightly discussing issues with layers in Flash, and my layers were shaking all around, but I discovered the problem.
My problem rooted in setting the X position of a single layer. As soon as I got rid of that action, my game ran perfectly fine in Flash.

Has this been identified as the problem yet, and is there any known workaround?
If not, what can I do to get distant background backdrops to scroll? My player does not move in the X direction, the objects move left past the player. I was moving the position of that single layer to simulate a parallax. How else can I move that layer? Or would it not cost much efficiency to use a 2x wide active and manipulate its X position?

This is a problem I tried to get rid of, but could not. Maybe I can try again, if you send me your application.