diff --git a/src/mac/carbon/menu.cpp b/src/mac/carbon/menu.cpp
index e81e6de61a..d0ba511b85 100644
--- a/src/mac/carbon/menu.cpp
+++ b/src/mac/carbon/menu.cpp
@@ -51,7 +51,8 @@ const short kwxMacAppleMenuId = 1 ;
 // ============================================================================
 // implementation
 // ============================================================================
-
+static void wxMenubarUnsetInvokingWindow( wxMenu *menu ) ;
+static void wxMenubarSetInvokingWindow( wxMenu *menu, wxWindow *win );
 
 // Menus
 
@@ -194,6 +195,12 @@ bool wxMenu::DoInsertOrAppend(wxMenuItem *pItem, size_t pos)
 			{
 				UMAInsertSubMenuItem(MAC_WXHMENU(m_hMenu), label , pos, pSubMenu->m_macMenuId);
 			}
+
+            // if adding a submenu to a menu already existing in the menu bar, we
+            // must set invoking window to allow processing events from this
+            // submenu
+            if ( m_invokingWindow )
+                wxMenubarSetInvokingWindow(pSubMenu, m_invokingWindow);
 		}
 		else
 		{
@@ -457,6 +464,7 @@ void wxMenuBar::Init()
 {
     m_eventHandler = this;
     m_menuBarFrame = NULL;
+    m_invokingWindow = (wxWindow*) NULL;
 }
 
 wxMenuBar::wxMenuBar()
@@ -557,6 +565,21 @@ void wxMenuBar::MacInstallMenuBar()
     }
 #endif
  
+    // clean-up the help menu before adding new items
+	MenuHandle mh = NULL ;
+	if ( UMAGetHelpMenu( &mh , &firstUserHelpMenuItem) == noErr )
+	{
+	    for ( int i = CountMenuItems( mh ) ; i >= firstUserHelpMenuItem ; --i )
+	    {
+	        DeleteMenuItem( mh , i ) ;
+	    }
+	}
+	else
+	{
+	    mh = NULL ;
+	}
+
+
    	for (size_t i = 0; i < m_menus.GetCount(); i++)
   	{
         Str255 	label;
@@ -567,16 +590,10 @@ void wxMenuBar::MacInstallMenuBar()
 
     	if( m_titles[i] == "?" || m_titles[i] == "&?"  || m_titles[i] == wxApp::s_macHelpMenuTitleName )
     	{
-			MenuHandle mh = NULL ;
-			if ( UMAGetHelpMenu( &mh , &firstUserHelpMenuItem) != noErr )
+			if ( mh == NULL )
 			{
 			    continue ;
 			}
-
-		    for ( int i = CountMenuItems( mh ) ; i >= firstUserHelpMenuItem ; --i )
-		    {
-		        DeleteMenuItem( mh , i ) ;
-		    }
 				
 		  	for (pos = 0 , node = menu->GetMenuItems().First(); node; node = node->Next(), pos++) 
 	  		{
@@ -862,6 +879,11 @@ bool wxMenuBar::Append(wxMenu *menu, const wxString& title)
         Refresh();
     }
 
+   // m_invokingWindow is set after wxFrame::SetMenuBar(). This call enables
+    // adding menu later on.
+    if (m_invokingWindow)
+        wxMenubarSetInvokingWindow( menu, m_invokingWindow );
+
     return TRUE;
 }
 
@@ -895,6 +917,7 @@ static void wxMenubarSetInvokingWindow( wxMenu *menu, wxWindow *win )
 
 void wxMenuBar::UnsetInvokingWindow()
 {
+    m_invokingWindow = (wxWindow*) NULL;
     wxMenuList::Node *node = m_menus.GetFirst();
     while (node)
     {
@@ -906,6 +929,7 @@ void wxMenuBar::UnsetInvokingWindow()
 
 void wxMenuBar::SetInvokingWindow(wxFrame *frame)
 {
+    m_invokingWindow = frame;
     wxMenuList::Node *node = m_menus.GetFirst();
     while (node)
     {
diff --git a/src/mac/menu.cpp b/src/mac/menu.cpp
index e81e6de61a..d0ba511b85 100644
--- a/src/mac/menu.cpp
+++ b/src/mac/menu.cpp
@@ -51,7 +51,8 @@ const short kwxMacAppleMenuId = 1 ;
 // ============================================================================
 // implementation
 // ============================================================================
-
+static void wxMenubarUnsetInvokingWindow( wxMenu *menu ) ;
+static void wxMenubarSetInvokingWindow( wxMenu *menu, wxWindow *win );
 
 // Menus
 
@@ -194,6 +195,12 @@ bool wxMenu::DoInsertOrAppend(wxMenuItem *pItem, size_t pos)
 			{
 				UMAInsertSubMenuItem(MAC_WXHMENU(m_hMenu), label , pos, pSubMenu->m_macMenuId);
 			}
+
+            // if adding a submenu to a menu already existing in the menu bar, we
+            // must set invoking window to allow processing events from this
+            // submenu
+            if ( m_invokingWindow )
+                wxMenubarSetInvokingWindow(pSubMenu, m_invokingWindow);
 		}
 		else
 		{
@@ -457,6 +464,7 @@ void wxMenuBar::Init()
 {
     m_eventHandler = this;
     m_menuBarFrame = NULL;
+    m_invokingWindow = (wxWindow*) NULL;
 }
 
 wxMenuBar::wxMenuBar()
@@ -557,6 +565,21 @@ void wxMenuBar::MacInstallMenuBar()
     }
 #endif
  
+    // clean-up the help menu before adding new items
+	MenuHandle mh = NULL ;
+	if ( UMAGetHelpMenu( &mh , &firstUserHelpMenuItem) == noErr )
+	{
+	    for ( int i = CountMenuItems( mh ) ; i >= firstUserHelpMenuItem ; --i )
+	    {
+	        DeleteMenuItem( mh , i ) ;
+	    }
+	}
+	else
+	{
+	    mh = NULL ;
+	}
+
+
    	for (size_t i = 0; i < m_menus.GetCount(); i++)
   	{
         Str255 	label;
@@ -567,16 +590,10 @@ void wxMenuBar::MacInstallMenuBar()
 
     	if( m_titles[i] == "?" || m_titles[i] == "&?"  || m_titles[i] == wxApp::s_macHelpMenuTitleName )
     	{
-			MenuHandle mh = NULL ;
-			if ( UMAGetHelpMenu( &mh , &firstUserHelpMenuItem) != noErr )
+			if ( mh == NULL )
 			{
 			    continue ;
 			}
-
-		    for ( int i = CountMenuItems( mh ) ; i >= firstUserHelpMenuItem ; --i )
-		    {
-		        DeleteMenuItem( mh , i ) ;
-		    }
 				
 		  	for (pos = 0 , node = menu->GetMenuItems().First(); node; node = node->Next(), pos++) 
 	  		{
@@ -862,6 +879,11 @@ bool wxMenuBar::Append(wxMenu *menu, const wxString& title)
         Refresh();
     }
 
+   // m_invokingWindow is set after wxFrame::SetMenuBar(). This call enables
+    // adding menu later on.
+    if (m_invokingWindow)
+        wxMenubarSetInvokingWindow( menu, m_invokingWindow );
+
     return TRUE;
 }
 
@@ -895,6 +917,7 @@ static void wxMenubarSetInvokingWindow( wxMenu *menu, wxWindow *win )
 
 void wxMenuBar::UnsetInvokingWindow()
 {
+    m_invokingWindow = (wxWindow*) NULL;
     wxMenuList::Node *node = m_menus.GetFirst();
     while (node)
     {
@@ -906,6 +929,7 @@ void wxMenuBar::UnsetInvokingWindow()
 
 void wxMenuBar::SetInvokingWindow(wxFrame *frame)
 {
+    m_invokingWindow = frame;
     wxMenuList::Node *node = m_menus.GetFirst();
     while (node)
     {