copy the actual tileSize object, not just the reference.

git-svn-id: http://svn.openlayers.org/trunk/openlayers@900 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Layer/Grid.js

@@ -65,6 +65,7 @@ OpenLayers.Layer.Grid.prototype =
         }
         
         // copy/set any non-init, non-simple values here
+        obj.tileSize = this.tileSize.copyOf();
         
         //get all additions from superclasses
         return OpenLayers.Layer.HTTPRequest.prototype.clone.apply(this, [obj]);