Path problem - going nuts here

The outcome of this code is really weird. Look at this code:

private function showStopmotionAnimation( pId:Number , pShow:Boolean ):Void
    {
        trace("******************************************************");
        trace("type :  = "+typeof(mPanoImg));
        trace("1 : "+mPanoImg);
        trace("2 : "+_level0.game_mc.container_mc.scroller_mc.image_mc["mc"+pId]);
        trace("3 : "+mPanoImg["mc"+pId]);
        trace("4 : "+mPanoImg.mc3);
    }

It outputs the following:

******************************************************
type :  = movieclip
1 : _level0.game_mc.container_mc.scroller_mc.image_mc
2 : _level0.game_mc.container_mc.scroller_mc.image_mc.mc3
3 : undefined
4 : undefined

I want to use the 3rd version:

mPanoImg["mc"+pId]

But it always returns undefined.
Do you get what the problem is? “mPanoImg” has been defined as a member of type MovieClip:

private var mPanoImg:MovieClip;

and later on

mPanoImg = mAssets.scroller_mc.createEmptyMovieClip( "image_mc" , 0 );

I have no idea what is happening here, never seen this before and i work a lot with Flash :frowning:

Here is my complete class, for those who are interested