New linked MC's not looking like original ones

Hi all,

trying to make a very small change to an animation i need to edit. I’m simply adding an extra button which links externally. The problem is, the code below makes the buttons change size and colour when hovered over and clicked. For some reason, anything i add doesn’t have the same effects, i’ve narrowed it down to this bit of code, is there something here thats telling flash to only apply the effects to buttons originally in the file? and not any others that i add (that are otherwise identical)

any help you can offer would be great!

function buttonOver(x) {
	x.gotoAndPlay("in");
}
function buttonOut(x) {
	x.gotoAndPlay("out");
}
function loadSection(x, y, z) {
	_parent.section_holder.x = y;
	_parent.section_holder.gotoAndPlay("out");
	x.gotoAndPlay("selected_in");
	z.enabled = false;
	n.gotoAndPlay("selected_out");
	o.enabled = true;
	n = x;
	o = z;
	if (x == tv || x == radio || x == gasp) {
		if (a == 1) {
		} else {
			unloadMovie("_parent.mp3_player_holder");
			a = 1;
		}
	} else {
		if (a == 1) {
			loadMovie("content/swf/mp3_player.swf", "_parent.mp3_player_holder");
			a = 0;
		}
	}
}