                 
         private function hidePopUp() : void {
             if (isDropDownOpen) {
-                popUp.popUp.removeEventListener(FlexMouseEvent.MOUSE_DOWN_OUTSIDE, onMouseDownOutside);
+                popUp.popUp.removeEventListener(FlexMouseEvent.MOUSE_DOWN_OUTSIDE, onMouseDownOutside);                
+                systemManager.removeEventListener(MouseEvent.MOUSE_WHEEL, onMouseWheel);
                 popUp.displayPopUp = false;
             }
         }

	import flash.display.DisplayObjectContainer;
	import flash.events.FocusEvent;
	import flash.events.KeyboardEvent;
	import flash.ui.Keyboard;
	
	import mx.collections.ArrayCollection;

                    list.selectedIndex = -1;
                }
                                        
                popUp.popUp.addEventListener(FlexMouseEvent.MOUSE_DOWN_OUTSIDE, onMouseDownOutside);                
                systemManager.addEventListener(MouseEvent.MOUSE_WHEEL, onMouseWheel);
            }
        }
        
