onPositionTarget callback: Proper implementation [SOLVED]

Hi All;

I have a set of objects instantiated and added to the scene graph, via an iteration, as:

$piece = new t2dStaticSprite(%addPiece) {
    imageMap = "dynamicImageMap";
    frame = (%i - 1);
    mUseSourceRect = "0";
    sourceRect = "0 0 0 0";
    canSaveDynamicFields = "1";
    UseMouseEvents = "1";
    Position = "-120.000 -200.000";
    size = $dimensions;
    Layer = "1";
    BlendIgnoreTextureAlpha = "1";
    UsesPhysics = "1";
    //UseUpdateCallback = "1";
    AutoMassInertia = "0";
    Mass = "64";
    Inertia = "68266.7";
    mountID = (%p + 1);
};

Each of these objects then has the capability of being moved (based on variables and gestures used). Here is an example of one such movement snippet:

%currentPiece.moveTo(%startX, (%startY - $gridCellSize), $speed, true, true, true, 0.1);

Now, I'm trying to prevent the user from initiating another move until the previous movement has completed (i.e. the last piece triggered to move has reached its destination). What I'm having a problem with, however, is getting the callback for moveTo (onPositionTarget) to work.

Everything exists on the same sceneWindow2D scene graph.

This is what I had implemented but it is never triggered:

// Callback for when a piece has successfully moved to its next position
function sceneWindow2D::onPositionTarget(%this)
{
	echo ("onPositionTarget callback called!");
	
	// Reset pieceMoving so new touch-moves can be registered
	$pieceMoving = 0;
}

I've added/removed the UseUpdateCallback on the scene itself, added/removed UseUpdateCallback on the object itself (which I don't even know whether it is proper), and rubbed my rabbit's foot. Alas, nothing seems to be working.

I'm hoping that I'm just having an off day and have simply mis-implemented this. Any feedback is greatly appreciated.

Thank you!