diff --git a/content/events/src/nsDOMEvent.cpp b/content/events/src/nsDOMEvent.cpp
index de6cbfb87825..06b788c659b5 100644
--- a/content/events/src/nsDOMEvent.cpp
+++ b/content/events/src/nsDOMEvent.cpp
@@ -1557,14 +1557,6 @@ nsDOMEvent::ReportWrongPropertyAccessWarning(const char* aPropertyName)
                                          "DOM Events");
 }
 
-NS_IMETHODIMP
-nsDOMEvent::GetPreventDefault(PRBool* aReturn)
-{
-  NS_ENSURE_ARG_POINTER(aReturn);
-  *aReturn = mEvent && (mEvent->flags & NS_EVENT_FLAG_NO_DEFAULT);
-  return NS_OK;
-}
-
 nsresult NS_NewDOMEvent(nsIDOMEvent** aInstancePtrResult,
                         nsPresContext* aPresContext,
                         nsEvent *aEvent) 
diff --git a/content/events/src/nsDOMUIEvent.cpp b/content/events/src/nsDOMUIEvent.cpp
index 663af34b5ff5..bc471fbb7ed5 100644
--- a/content/events/src/nsDOMUIEvent.cpp
+++ b/content/events/src/nsDOMUIEvent.cpp
@@ -368,6 +368,15 @@ nsDOMUIEvent::GetIsChar(PRBool* aIsChar)
   }
 }
 
+NS_IMETHODIMP
+nsDOMUIEvent::GetPreventDefault(PRBool* aReturn)
+{
+  NS_ENSURE_ARG_POINTER(aReturn);
+  *aReturn = mEvent && (mEvent->flags & NS_EVENT_FLAG_NO_DEFAULT);
+
+  return NS_OK;
+}
+
 NS_METHOD nsDOMUIEvent::GetCompositionReply(nsTextEventReply** aReply)
 {
   if((mEvent->message == NS_COMPOSITION_START) ||
diff --git a/content/events/src/nsDOMUIEvent.h b/content/events/src/nsDOMUIEvent.h
index 5f6514da1150..0ad95145102a 100644
--- a/content/events/src/nsDOMUIEvent.h
+++ b/content/events/src/nsDOMUIEvent.h
@@ -71,7 +71,6 @@ public:
   // Forward to nsDOMEvent
   NS_FORWARD_TO_NSDOMEVENT
 
-  NS_FORWARD_NSIDOMNSEVENT(nsDOMEvent::)
 protected:
 
   // Internal helper functions
diff --git a/content/events/src/nsEventDispatcher.cpp b/content/events/src/nsEventDispatcher.cpp
index 76f22e1922b8..813865320fe3 100644
--- a/content/events/src/nsEventDispatcher.cpp
+++ b/content/events/src/nsEventDispatcher.cpp
@@ -325,6 +325,8 @@ nsEventTargetChainItem::HandleEventTargetChain(nsEventChainPostVisitor& aVisitor
     if (!(aVisitor.mEvent->flags & NS_EVENT_FLAG_CANT_BUBBLE) || newTarget) {
       if ((!(aVisitor.mEvent->flags & NS_EVENT_FLAG_NO_CONTENT_DISPATCH) ||
            item->ForceContentDispatch()) &&
+          (!(aFlags & NS_EVENT_FLAG_SYSTEM_EVENT) ||
+           aVisitor.mEventStatus != nsEventStatus_eConsumeNoDefault) &&
           !(aVisitor.mEvent->flags & NS_EVENT_FLAG_STOP_DISPATCH)) {
         item->HandleEvent(aVisitor, aFlags & NS_EVENT_BUBBLE_MASK,
                           createdELMs != nsEventListenerManager::sCreatedCount);
diff --git a/content/xbl/src/nsXBLBinding.cpp b/content/xbl/src/nsXBLBinding.cpp
index 0b84dbd556e0..0aaf01597ac2 100644
--- a/content/xbl/src/nsXBLBinding.cpp
+++ b/content/xbl/src/nsXBLBinding.cpp
@@ -863,8 +863,7 @@ nsXBLBinding::InstallEventHandlers()
         // This is a weak ref. systemEventGroup above is already a
         // strong ref, so we are guaranteed it will not go away.
         nsIDOMEventGroup* eventGroup = nsnull;
-        if ((isChromeDoc || mBoundElement->IsInNativeAnonymousSubtree()) &&
-            (curr->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM))) {
+        if (curr->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM)) {
           if (!systemEventGroup)
             manager->GetSystemEventGroupLM(getter_AddRefs(systemEventGroup));
           eventGroup = systemEventGroup;
@@ -902,8 +901,7 @@ nsXBLBinding::InstallEventHandlers()
         // This is a weak ref. systemEventGroup above is already a
         // strong ref, so we are guaranteed it will not go away.
         nsIDOMEventGroup* eventGroup = nsnull;
-        if ((isChromeDoc || mBoundElement->IsInNativeAnonymousSubtree()) &&
-            (handler->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM))) {
+        if (handler->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM)) {
           if (!systemEventGroup)
             manager->GetSystemEventGroupLM(getter_AddRefs(systemEventGroup));
           eventGroup = systemEventGroup;
@@ -1001,9 +999,7 @@ nsXBLBinding::UnhookEventHandlers()
     if (!manager) {
       return;
     }
-
-    PRBool isChromeDoc =
-      nsContentUtils::IsChromeDoc(mBoundElement->GetOwnerDoc());
+                                      
     nsCOMPtr<nsIDOMEventGroup> systemEventGroup;
     nsXBLPrototypeHandler* curr;
     for (curr = handlerChain; curr; curr = curr->GetNextHandler()) {
@@ -1032,8 +1028,7 @@ nsXBLBinding::UnhookEventHandlers()
       // This is a weak ref. systemEventGroup above is already a
       // strong ref, so we are guaranteed it will not go away.
       nsIDOMEventGroup* eventGroup = nsnull;
-      if ((isChromeDoc || mBoundElement->IsInNativeAnonymousSubtree()) &&
-          (curr->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM))) {
+      if (curr->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM)) {
         if (!systemEventGroup)
           manager->GetSystemEventGroupLM(getter_AddRefs(systemEventGroup));
         eventGroup = systemEventGroup;
@@ -1061,8 +1056,7 @@ nsXBLBinding::UnhookEventHandlers()
       // This is a weak ref. systemEventGroup above is already a
       // strong ref, so we are guaranteed it will not go away.
       nsIDOMEventGroup* eventGroup = nsnull;
-      if ((isChromeDoc || mBoundElement->IsInNativeAnonymousSubtree()) &&
-          (handler->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM))) {
+      if (handler->GetType() & (NS_HANDLER_TYPE_XBL_COMMAND | NS_HANDLER_TYPE_SYSTEM)) {
         if (!systemEventGroup)
           manager->GetSystemEventGroupLM(getter_AddRefs(systemEventGroup));
         eventGroup = systemEventGroup;
diff --git a/content/xul/content/src/nsXULElement.cpp b/content/xul/content/src/nsXULElement.cpp
index 65b4b127e77f..e2b21508acdf 100644
--- a/content/xul/content/src/nsXULElement.cpp
+++ b/content/xul/content/src/nsXULElement.cpp
@@ -140,8 +140,7 @@
 #include "nsFrameLoader.h"
 #include "prlog.h"
 #include "rdf.h"
-#include "nsIDOM3EventTarget.h"
-#include "nsIDOMEventGroup.h"
+
 #include "nsIControllers.h"
 
 // The XUL doc interface
@@ -1565,17 +1564,6 @@ nsXULElement::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
 {
     aVisitor.mForceContentDispatch = PR_TRUE; //FIXME! Bug 329119
     nsIAtom* tag = Tag();
-    if (IsRootOfNativeAnonymousSubtree() &&
-        (tag == nsGkAtoms::scrollbar || tag == nsGkAtoms::scrollcorner) &&
-        (aVisitor.mEvent->message == NS_MOUSE_CLICK ||
-         aVisitor.mEvent->message == NS_MOUSE_DOUBLECLICK ||
-         aVisitor.mEvent->message == NS_XUL_COMMAND ||
-         aVisitor.mEvent->message == NS_CONTEXTMENU)) {
-        // Don't propagate these events from native anonymous scrollbar.
-        aVisitor.mCanHandle = PR_TRUE;
-        aVisitor.mParentTarget = nsnull;
-        return NS_OK;
-    }
     if (aVisitor.mEvent->message == NS_XUL_COMMAND &&
         aVisitor.mEvent->originalTarget == static_cast<nsIContent*>(this) &&
         tag != nsGkAtoms::command) {
@@ -2168,19 +2156,13 @@ PopupListenerPropertyDtor(void* aObject, nsIAtom* aPropertyName,
   if (!listener) {
     return;
   }
-  nsCOMPtr<nsIDOM3EventTarget> target =
+  nsCOMPtr<nsIDOMEventTarget> target =
     do_QueryInterface(static_cast<nsINode*>(aObject));
   if (target) {
-    nsCOMPtr<nsIDOMEventGroup> systemGroup;
-    static_cast<nsPIDOMEventTarget*>(aObject)->
-      GetSystemEventGroup(getter_AddRefs(systemGroup));
-    if (systemGroup) {
-      target->RemoveGroupedEventListener(NS_LITERAL_STRING("mousedown"),
-                                         listener, PR_FALSE, systemGroup);
-
-      target->RemoveGroupedEventListener(NS_LITERAL_STRING("contextmenu"),
-                                         listener, PR_FALSE, systemGroup);
-    }
+    target->RemoveEventListener(NS_LITERAL_STRING("mousedown"), listener,
+                                PR_FALSE);
+    target->RemoveEventListener(NS_LITERAL_STRING("contextmenu"), listener,
+                                PR_FALSE);
   }
   NS_RELEASE(listener);
 }
@@ -2202,17 +2184,13 @@ nsXULElement::AddPopupListener(nsIAtom* aName)
         return NS_OK;
     }
 
-    nsCOMPtr<nsIDOMEventGroup> systemGroup;
-    GetSystemEventGroup(getter_AddRefs(systemGroup));
-    NS_ENSURE_STATE(systemGroup);
-
     nsresult rv = NS_NewXULPopupListener(this, isContext,
                                          getter_AddRefs(popupListener));
     if (NS_FAILED(rv))
         return rv;
 
     // Add the popup as a listener on this element.
-    nsCOMPtr<nsIDOM3EventTarget> target(do_QueryInterface(static_cast<nsIContent *>(this)));
+    nsCOMPtr<nsIDOMEventTarget> target(do_QueryInterface(static_cast<nsIContent *>(this)));
     NS_ENSURE_TRUE(target, NS_ERROR_FAILURE);
     rv = SetProperty(listenerAtom, popupListener, PopupListenerPropertyDtor,
                      PR_TRUE);
@@ -2220,14 +2198,10 @@ nsXULElement::AddPopupListener(nsIAtom* aName)
     // Want the property to have a reference to the listener.
     nsIDOMEventListener* listener = nsnull;
     popupListener.swap(listener);
-
-    if (isContext) {
-      target->AddGroupedEventListener(NS_LITERAL_STRING("contextmenu"),
-                                      listener, PR_FALSE, systemGroup);
-    } else {
-      target->AddGroupedEventListener(NS_LITERAL_STRING("mousedown"),
-                                      listener, PR_FALSE, systemGroup);
-    }
+    if (isContext)
+      target->AddEventListener(NS_LITERAL_STRING("contextmenu"), listener, PR_FALSE);
+    else
+      target->AddEventListener(NS_LITERAL_STRING("mousedown"), listener, PR_FALSE);
     return NS_OK;
 }
 
diff --git a/content/xul/content/test/Makefile.in b/content/xul/content/test/Makefile.in
index 411032315310..c42b4f7abeaf 100644
--- a/content/xul/content/test/Makefile.in
+++ b/content/xul/content/test/Makefile.in
@@ -46,7 +46,6 @@ include $(topsrcdir)/config/rules.mk
 
 _TEST_FILES = 	test_bug330705-2.xul \
 		test_bug233643.xul \
-		test_bug486990.xul \
 		$(NULL)
 	
 _CHROME_FILES = \
diff --git a/content/xul/content/test/test_bug486990.xul b/content/xul/content/test/test_bug486990.xul
deleted file mode 100644
index 309eeee75fc6..000000000000
--- a/content/xul/content/test/test_bug486990.xul
+++ /dev/null
@@ -1,168 +0,0 @@
-<?xml version="1.0"?>
-<?xml-stylesheet type="text/css" href="chrome://global/skin"?>
-<?xml-stylesheet type="text/css" href="/tests/SimpleTest/test.css"?>
-<!--
-https://bugzilla.mozilla.org/show_bug.cgi?id=486990
--->
-<window title="Mozilla Bug 486990"
-        xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
-        onload="setTimeout(runTests, 0);">
-  <script type="application/javascript" src="/MochiKit/packed.js"/>
-  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"/>
-  <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"/>
-
-  <!-- test results are displayed in the html:body -->
-  <body xmlns="http://www.w3.org/1999/xhtml">
-  <a href="https://bugzilla.mozilla.org/show_bug.cgi?id=486990"
-     target="_blank">Mozilla Bug 486990</a>
-
-  </body>
-  <div xmlns="http://www.w3.org/1999/xhtml">
-  <select size="5" id="select">
-    <option>1</option>
-    <option>2</option>
-    <option>3</option>
-    <option>4</option>
-    <option>5</option>
-    <option>6</option>
-    <option>7</option>
-    <option>8</option>
-    <option>9</option>
-    <option>10</option>
-  </select>
-  </div>
-  <menupopup id="cm" onpopupshowing="popupShowing(event);">
-    <menuitem label="Mozilla" value="http://mozilla.org"/>
-    <menuitem label="Slashdot" value="http://slashdot.org"/>
-    <menuitem label="Sourceforge" value="http://sf.net"/>
-    <menuitem label="Freshmeat" value="http://freshmeat.net"/>
-  </menupopup>
-  <button label="test button" contextmenu="cm" id="testbutton"/>
-  
-  <!-- test code goes here -->
-  <script type="application/javascript">
-  <![CDATA[
-
-  /** Test for Bug 486990 **/
-
-  SimpleTest.waitForExplicitFinish();
-
-  var prevented = false;
-  var eventCount = 0;
-
-  function fooListener(evt) {
-    evt.preventDefault();
-    prevented = evt.getPreventDefault();
-    ++eventCount;
-  };
-
-  var clickCount = 0;
-  var mouseDownCount = 0;
-  var mouseUpCount = 0;
-  function clickListener(evt) {
-    ++clickCount;
-  }
-
-  function mouseDownListener(evt) {
-    ++mouseDownCount;
-  }
-
-  function mouseUpListener(evt) {
-    ++mouseUpCount;
-  }
-
-  var popupshowingcount = 0;
-
-  function popupShowing(evt) {
-    ++popupshowingcount;
-    evt.preventDefault();
-  }
-
-  function contextMenuStopper(evt) {
-    evt.stopPropagation();
-  }
-
-  function contextMenuPreventer(evt) {
-    evt.preventDefault();
-  }
-
-  function allowDisableContextMenu(allow) {
-    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
-    const prefSvcContractID = "@mozilla.org/preferences-service;1";
-    const prefSvcIID = Components.interfaces.nsIPrefService;
-    var prefs = Components.classes[prefSvcContractID].getService(prefSvcIID)
-                                                     .getBranch("dom.event.contextmenu.");
-    try {
-      if (allow) {
-        prefs.clearUserPref("enabled");
-      } else {
-        prefs.setBoolPref("enabled", allow);
-      }
-    } catch(ex) {}
-  }
-  
-  function runTests() {
-    document.addEventListener("foo", fooListener, true);
-    var e1 = document.createEvent("Event");
-    e1.initEvent("foo", true, true);
-    document.dispatchEvent(e1);
-    is(eventCount, 1, "Wrong event count");
-    ok(prevented, "Default handling should have been prevented.");
-
-    prevented = false;
-    var e2 = document.createEvent("Event");
-    e2.initEvent("foo", false, false);
-    document.dispatchEvent(e1);
-    is(eventCount, 2, "Wrong event count");
-    ok(prevented, "Default handling should have been prevented.");
-
-    var tb = document.getElementById("testbutton");
-    dispatchTrustedContextMenuEvent(tb);
-    is(popupshowingcount, 1, "Should have got 'popupShowing' event!");
-
-    tb.addEventListener("contextmenu", contextMenuStopper, true);
-    dispatchTrustedContextMenuEvent(tb);
-    is(popupshowingcount, 2, "Should have got 'popupShowing' event!");
-
-    tb.addEventListener("contextmenu", contextMenuPreventer, true);
-    dispatchTrustedContextMenuEvent(tb);
-    is(popupshowingcount, 2, "Should not have got 'popupShowing' event!");
-
-    allowDisableContextMenu(false);
-    dispatchTrustedContextMenuEvent(tb);
-    is(popupshowingcount, 3, "Should have got 'popupShowing' event!");
-
-    allowDisableContextMenu(true);
-    dispatchTrustedContextMenuEvent(tb);
-    is(popupshowingcount, 3, "Should not have got 'popupshowing' event!");
-
-    var s = document.getElementById("select");
-    s.addEventListener("click", clickListener, true);
-    s.addEventListener("mousedown", mouseDownListener, true);
-    s.addEventListener("mouseup", mouseUpListener, true);
-
-    synthesizeMouse(s, 1, 10, {}, window);
-    is(clickCount, 1, "Should have got click event!");
-    is(mouseDownCount, 1, "Should have got mousedown event!");
-    is(mouseUpCount, 1, "Should have got mouseup event!");
-
-    // Dispatch to scrollbar.
-    synthesizeMouse(s, s.getBoundingClientRect().right - 3, 10, {}, window);
-    is(clickCount, 1, "Should not have got click event!");
-    is(mouseDownCount, 2, "Should have got mousedown event!");
-    is(mouseUpCount, 2, "Should have got mouseup event!");
-
-    SimpleTest.finish();
-  }
-
-  function dispatchTrustedContextMenuEvent(target) {
-    netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
-    var e = document.createEvent("MouseEvent");
-    e.initMouseEvent("contextmenu", true, true, window, 0, 0, 0, 0, 0, 
-                      false, false, false, false, 2, null);
-    return target.dispatchEvent(e);
-  }
-
-  ]]>
-  </script>
-</window>
diff --git a/dom/interfaces/events/nsIDOMNSEvent.idl b/dom/interfaces/events/nsIDOMNSEvent.idl
index d01fe33a4c46..4abdfb4d0388 100644
--- a/dom/interfaces/events/nsIDOMNSEvent.idl
+++ b/dom/interfaces/events/nsIDOMNSEvent.idl
@@ -44,7 +44,7 @@
 #endif
 %}
 
-[scriptable, uuid(9be8096b-f795-4045-9664-0c275f36fe5b)]
+[scriptable, uuid(e565d518-4510-407f-a3d9-3b4107549c6d)]
 interface nsIDOMNSEvent : nsISupports
 {
   const long MOUSEDOWN    = 0x00000001;
@@ -114,7 +114,5 @@ interface nsIDOMNSEvent : nsISupports
    */
   void                      preventCapture();
 
-  boolean                   getPreventDefault();
-
   readonly attribute boolean isTrusted;
 };
diff --git a/dom/interfaces/events/nsIDOMNSUIEvent.idl b/dom/interfaces/events/nsIDOMNSUIEvent.idl
index fdabbdcaf46e..5592478dc07b 100644
--- a/dom/interfaces/events/nsIDOMNSUIEvent.idl
+++ b/dom/interfaces/events/nsIDOMNSUIEvent.idl
@@ -37,14 +37,16 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-#include "nsIDOMNSEvent.idl"
+#include "domstubs.idl"
 
-[scriptable, uuid(72c9f79c-98cd-4224-a467-86b59c0a38f7)]
-interface nsIDOMNSUIEvent : nsIDOMNSEvent
+[scriptable, uuid(a6cf90c4-15b3-11d2-932e-00805f8add32)]
+interface nsIDOMNSUIEvent : nsISupports
 {
   const long SCROLL_PAGE_UP = -32768;
   const long SCROLL_PAGE_DOWN = 32768;
 
+  boolean                   getPreventDefault();
+
   readonly attribute long             layerX;
   readonly attribute long             layerY;
   readonly attribute long             pageX;
diff --git a/js/src/xpconnect/src/dom_quickstubs.qsconf b/js/src/xpconnect/src/dom_quickstubs.qsconf
index 596063eb45ab..f5c2a3476c33 100644
--- a/js/src/xpconnect/src/dom_quickstubs.qsconf
+++ b/js/src/xpconnect/src/dom_quickstubs.qsconf
@@ -283,7 +283,6 @@ members = [
     'nsIDOMMouseEvent.screenX',
     'nsIDOMNSEvent.originalTarget',
     'nsIDOMNSEvent.preventCapture',
-    'nsIDOMNSEvent.getPreventDefault',
     'nsIDOMKeyEvent.ctrlKey',
     'nsIDOMKeyEvent.shiftKey',
     'nsIDOMKeyEvent.keyCode',
@@ -295,6 +294,7 @@ members = [
     'nsIDOMMutationEvent.attrChange',
     'nsIDOMMutationEvent.newValue',
     'nsIDOMMutationEvent.prevValue',
+    'nsIDOMNSUIEvent.getPreventDefault',
     'nsIDOMNSUIEvent.which',
     'nsIDOMNSUIEvent.rangeParent',
     'nsIDOMNSUIEvent.rangeOffset',
diff --git a/security/manager/ssl/src/nsSmartCardEvent.cpp b/security/manager/ssl/src/nsSmartCardEvent.cpp
index d312d43d26c7..2b5df868508c 100644
--- a/security/manager/ssl/src/nsSmartCardEvent.cpp
+++ b/security/manager/ssl/src/nsSmartCardEvent.cpp
@@ -186,12 +186,6 @@ NS_IMETHODIMP nsSmartCardEvent::GetIsTrusted(PRBool *aIsTrusted)
   return mNSEvent->GetIsTrusted(aIsTrusted);
 }
 
-NS_IMETHODIMP
-nsSmartCardEvent::GetPreventDefault(PRBool* aReturn)
-{
-  NS_ASSERTION(mNSEvent, "SmartCardEvent called without Init");
-  return mNSEvent->GetPreventDefault(aReturn);
-}
 
 // IDOMEvent maps
 NS_IMETHODIMP nsSmartCardEvent::GetType(nsAString & aType)
diff --git a/toolkit/content/widgets/popup.xml b/toolkit/content/widgets/popup.xml
index 753778c2a9cd..105c3f6e19b5 100644
--- a/toolkit/content/widgets/popup.xml
+++ b/toolkit/content/widgets/popup.xml
@@ -174,6 +174,8 @@
     </implementation>
 
     <handlers>
+      <handler event="contextmenu" action="event.preventDefault();"/>
+
       <handler event="popupshowing" phase="target">
         <![CDATA[
           var array = [];