[MX2004]need help making movieclips invisible on load

I have several movieclips placed on the timeline that I want to be invisible and not run until the user clicks a button. The movieclips are linked to a class I set up:

class Hidestop extends MovieClip {
    function onLoad() {
        this._visible = false;
        this.stop();
    }
}

The problem is that some, but not all, movieclips show briefly when they load before becoming invisible. I can get around this by starting each movieclip with a blank frame, but there must be a better way. Any help appreciated!