Index: lib/OpenLayers/BaseTypes.js
===================================================================
--- lib/OpenLayers/BaseTypes.js	(revision 2858)
+++ lib/OpenLayers/BaseTypes.js	(working copy)
@@ -23,6 +23,18 @@
                 arguments[i] = new mixin(OpenLayers.Class.isPrototype);
             }
             OpenLayers.Util.extend(proto, arguments[i]);
+
+            // This is a hack for IE see
+            // http://trac.openlayers.org/attachment/ticket/552
+            // 
+            // The problem is that ie doesnt recognize toString as a property
+            //  so the util.extend() doesnt copy it over. we do it manually.
+            // 
+            // to be revisited in 3.0
+            // 
+            if (arguments[i].toString) {
+                proto.toString = arguments[i].toString;
+            }
         }
         return proto;
     }