         // Take the PopUpAnchor's concatenatedMatrix 
         // and subtract out the popUp parent's concatenatedMatrix
         var matrix:Matrix = systemManager.getSandboxRoot().transform.concatenatedMatrix;
-        matrix.invert();
-        matrix.concat(MatrixUtil.getConcatenatedMatrix(this));
+        
+        if (matrix)
+        {
+            matrix.invert();
+            matrix.concat(MatrixUtil.getConcatenatedMatrix(this));
+        }
         
         return matrix;
     }

        if (!addedToStage)
            return;
        
        /*if (popUpFactory && popUp == null && displayPopUp)
        {
            _popUp = UIComponent(popUpFactory.getInstance());
            _popUp.styleName = this
        }*/
        
        if (popUp == null)
            return;
                        

        return _displayPopUp;
    }


    
    //----------------------------------
    //  popUp
