Fixed plugins.

raphael.js

@@ -591,13 +591,16 @@ window.Raphael = (function () {
         }
         }
     },
     },
         plugins = function (con, add) {
         plugins = function (con, add) {
+            var that = this;
             for (var prop in add) if (add.hasOwnProperty(prop) && !(prop in con)) {
             for (var prop in add) if (add.hasOwnProperty(prop) && !(prop in con)) {
                 switch (typeof add[prop]) {
                 switch (typeof add[prop]) {
                     case "function":
                     case "function":
-                    con[prop] = con === this ? add[prop] : function () { return add[prop].apply(this, arguments); };
+                        (function (f) {
+                            con[prop] = con === that ? f : function () { return f.apply(that, arguments); };
+                        })(add[prop]);
                     break;
                     break;
                     case "object":
                     case "object":
-                    con[prop] = {};
+                        con[prop] = con[prop] || {};
                         plugins.call(this, con[prop], add[prop]);
                         plugins.call(this, con[prop], add[prop]);
                     break;
                     break;
                     default:
                     default: