Index: bridge/lib/prototype/dom.js
===================================================================
--- bridge/lib/prototype/dom.js	(revision 130)
+++ bridge/lib/prototype/dom.js	(working copy)
@@ -7978,7 +7978,9 @@
             // e.g.: $(element).stopObserving();
             registry.each(function(pair) {
                 var eventName = pair.key;
-                stopObserving(element, eventName);
+                if (eventName) {
+                    stopObserving(element, eventName);
+                }
             });
             return element;
         }
@@ -7990,7 +7992,9 @@
             // We stop observing all handlers for the given eventName.
             // e.g.: $(element).stopObserving('click');
             responders.each(function(r) {
-                stopObserving(element, eventName, r.handler);
+                if (r.handler) {
+                    stopObserving(element, eventName, r.handler);
+                }
             });
             return element;
         }
@@ -8022,7 +8026,6 @@
         }
 
         registry.set(eventName, responders.without(responder));
-
         return element;
     }