swapDepths on buttons

I’m in a bit of a dill pickle. I have a banner I’m working on and it has 28 icons that are button symbols. Each one when you mouse over, has a label animate out of it. All of these icons are in very close proximity and when you mouse over, the label usually goes behind the other icons.

Now usually, with movieclips I attach this:

MC.onRollOver = function (){
    _root.x += 2;
    this.swapDepths(_root.x);
}

Now if I apply this same code to a button, the swapDepths no longer works. I even tried to target the labels MC inside the button’s over frame but that only moved it to the foreground of inside that MC… not within the whole movie.

Does anyone know how to get the button which is being rolled over to be in focus?