Exported MapImage shifts on the map

[GennadyOster]

Hi All !

Environment: ArcGIS Server 10.0, Flex viewer 2.4, Flex API 2.4, Flex Builder 4.5

I need to show the exported image of the layer on the map.
Here is the code:

   private var designLand:ArcGISDynamicMapServiceLayer;
   private var layerImage:MapImageLayer;


                                                   ......

    layerImage = new MapImageLayer();
    layerImage.id = "designLand";
    map.addLayer(layerImage);
    designLand = new ArcGISDynamicMapServiceLayer(landURL);
   
                                                   ......                                             

    var pars:ImageParameters = new ImageParameters();
    var layerDefs:Array = new Array();
    pars.dpi = 96;
    pars.extent = map.extent;
    pars.format = "png8";
    pars.imageSpatialReference = map.spatialReference;
    layerDefs[layerID] = expression;  // The list of where conditions
    pars.layerDefinitions = layerDefs;
    pars.layerIds = [layerID];
    pars.layerOption = "show";  // For sure
    pars.transparent = true;
    
    pars.width = map.width;
    pars.height = map.height;
    
    designLand.exportMapImage(pars,new AsyncResponder(onExportComplete,onExportFault));

                                                    .........

   private function onExportComplete(img:MapImage, event:MapImageEvent):void
   {
   // var mi:MapImage = new MapImage();
   // mi.extent = map.extent;
   // mi.href = img.href;
    layerImage.removeAll();
    layerImage.alpha = 0.5; 
   // layerImage.add(mi);
    layerImage.add(img);
    layerImage.visible = true;
   }

The image created OK, all MapImage parameters (extent,spatial reference,width,height) seem to be OK, only the initial extent of the MapImageLayer stays default.
But image is shown with shift down, under the bottom boundary of the screen.
Can somebody please explain, what I'm doing wrong.

Thanks in advance.
Regards,
Gennady