MOUSE_OVER and nested movie clips problem

Hi,

I have a situation where i create a parent movie clip and use addChild() method to add couple more movie clips (circle shapes from library) to it (with space between them naturally since child objects are circles). When i set onRollOver event for my main movie clip it gets triggered in fact when i roll over it’s child objects(circles) and rolling over space between them will in fact trigger rollOut event which i don’t want. I would like to use onRollOver on my whole main movie clip with its child circles so if anyone could help i would really appreciate it. Here is a sample code i am using:

var mainMC:MovieClip = new MovieClip();
var childMC:Array = new Array();

for (var i:uint=0; i <5; i++){
  childMC* = new Circle();   //Circle is 'circle' shape attached from library
  mainMC.addChild(childMC);
}

stage.addChild(mainMC);

mainMC.addEventListener(MouseEvent.ROLL_OVER, mainOver);
mainMC.addEventListener(MouseEvent.ROLL_OUT, mainOut);

...

thanks,
best regards