     private function mouseDownHandler(event:MouseEvent):void
     {
         systemManager.getSandboxRoot().addEventListener(MouseEvent.MOUSE_UP, 
-                                                        system_mouseUpSomewhereHandler);
+                                                        system_mouseUpSomewhereHandler, true);
         systemManager.getSandboxRoot().addEventListener(SandboxMouseEvent.MOUSE_UP_SOMEWHERE, 
                                                         system_mouseUpSomewhereHandler);
         

     *  the mouse down point in clickOffset.
     */
    protected function thumb_mouseDownHandler(event:MouseEvent):void
    {
        addSystemHandlers(MouseEvent.MOUSE_MOVE, system_mouseMoveHandler, stage_mouseMoveHandler);
        addSystemHandlers(MouseEvent.MOUSE_UP, system_mouseUpHandler, stage_mouseUpHandler);
        clickOffset = thumb.globalToLocal(new Point(event.stageX, event.stageY));
        dispatchEvent(new TrackBaseEvent(TrackBaseEvent.THUMB_PRESS));
    }
    
    /**
     *  @private
     *  Capture mouse-move events on the thumb anywhere on the stage
     */
    private function stage_mouseMoveHandler(event:MouseEvent):void
    {
        if (event.target != stage)
            return;

        system_mouseMoveHandler(event);
    }

    /**

    override protected function focusOutHandler(event:FocusEvent):void
    {
        super.focusOutHandler(event);
        systemManager.getSandboxRoot().removeEventListener(MouseEvent.MOUSE_WHEEL, system_mouseWheelHandler);
    }
    
    /**
