diff -r 52f68c95e025 Lib/idlelib/EditorWindow.py
--- a/Lib/idlelib/EditorWindow.py	Thu Jan 26 08:47:27 2012 -0600
+++ b/Lib/idlelib/EditorWindow.py	Sat Jan 28 15:50:32 2012 -0600
@@ -393,14 +393,15 @@
         self.menudict = menudict = {}
         for name, label in self.menu_specs:
             underline, label = prepstr(label)
-            menudict[name] = menu = Menu(mbar, name=name)
+            menudict[name] = menu = Menu(mbar, name=name, tearoff=0)
             mbar.add_cascade(label=label, menu=menu, underline=underline)
         if macosxSupport.isCarbonAquaTk(self.root):
             # Insert the application menu
-            menudict['application'] = menu = Menu(mbar, name='apple')
+            menudict['application'] = menu = Menu(mbar, name='apple',
+                                                  tearoff=0)
             mbar.add_cascade(label='IDLE', menu=menu)
         self.fill_menus()
-        self.recent_files_menu = Menu(self.menubar)
+        self.recent_files_menu = Menu(self.menubar, tearoff=0)
         self.menudict['file'].insert_cascade(3, label='Recent Files',
                                              underline=0,
                                              menu=self.recent_files_menu)
diff -r 52f68c95e025 Lib/idlelib/macosxSupport.py
--- a/Lib/idlelib/macosxSupport.py	Thu Jan 26 08:47:27 2012 -0600
+++ b/Lib/idlelib/macosxSupport.py	Sat Jan 28 15:50:32 2012 -0600
@@ -98,7 +98,7 @@
     root.configure(menu=menubar)
     menudict = {}
 
-    menudict['windows'] = menu = Menu(menubar, name='windows')
+    menudict['windows'] = menu = Menu(menubar, name='windows', tearoff=0)
     menubar.add_cascade(label='Window', menu=menu, underline=0)
 
     def postwindowsmenu(menu=menu):
@@ -144,7 +144,8 @@
 
     if isCarbonAquaTk(root):
         # for Carbon AquaTk, replace the default Tk apple menu
-        menudict['application'] = menu = Menu(menubar, name='apple')
+        menudict['application'] = menu = Menu(menubar, name='apple',
+                                              tearoff=0)
         menubar.add_cascade(label='IDLE', menu=menu)
         Bindings.menudefs.insert(0,
             ('application', [