Index: lib/OpenLayers/Layer/MapGuide.js
===================================================================
--- lib/OpenLayers/Layer/MapGuide.js	(revision 8066)
+++ lib/OpenLayers/Layer/MapGuide.js	(working copy)
@@ -24,6 +24,13 @@
     isBaseLayer: true,
     
     /** 
+     * APIProperty: useOverlay
+     * {Boolean} flag to indicate if the layer should be retrieved using
+     * GETMAPIMAGE (default) or using GETDYNAMICOVERLAY requests.
+     **/
+    useOverlay: false,
+    
+    /** 
      * APIProperty: singleTile
      * {Boolean} use tile server or request single tile image. Note that using
      *    singleTile *and* isBaseLayer false is *not recommend*: it uses synchronous
@@ -127,6 +134,9 @@
                            this.params,
                            this.SINGLE_TILE_PARAMS
                            );
+            if (options.useOverlay!=null) {
+              this.useOverlay = options.useOverlay;
+            }
                            
         } else {
             //initialize for tiled layers
@@ -202,7 +212,7 @@
           params.setviewcentery = center.lat;
           params.setviewscale = this.map.getScale();
           
-          if (!this.isBaseLayer) {
+          if (this.useOverlay) {
             // in this case the main image operation is remapped to this
             this.params.operation = "GETDYNAMICMAPOVERLAYIMAGE";