Another setChildIndex problem

[imagesinmotion]

I'm having reel trouble trying to bring a movieclip to the front using setChildIndex.

I have 3 movieclips that are being loaded into a movieclip that sits on the stage.

I'm using:
var targetClip=event.currentTarget;
This the targeted clip into the var targetClip. I then use this var to tween the movieclip.

But when I use:
setChildIndex(targetClip, numChildren-1);
Using the same var targetClip to bring it to the front it doesn't work.

example is attached. I've commented out the:
//setChildIndex(targetClip, numChildren-1);

download example to have a better look if it helps
Cheers