Button moved and resized - And doesn't exist on trace

I’m totally confused. When I am designing in Flash CS3 Professional, I’ve got an instance of a movieclip that looks like this:

But when running the swf, it looks like this:

There is no ActionScript code anywhere that moves this button. I can’t see any reason why this button is suddenly moved.
Also, the component name of this button is ‘btnPlus’, and if I would try to trace this button with the code “trace(btnPlus);” in this frame, it gives an error saying “1120: Access of undefined property btnPlus.”