diff --git a/src/Menus.cpp b/src/Menus.cpp
index fe0259193..9dfda2a2e 100644
--- a/src/Menus.cpp
+++ b/src/Menus.cpp
@@ -548,9 +548,30 @@ void AudacityProject::CreateMenusAndCommands()
 
    c->AddSeparator();
 
+   // History window should be available either for UndoAvailableFlag or RedoAvailableFlag, 
+   // but we can't make the AddItem flags and mask have both, because they'd both have to be true for the 
+   // command to be enabled. 
+   //    If user has Undone the entire stack, RedoAvailableFlag is on but UndoAvailableFlag is off.
+   //    If user has done things but not Undone anything, RedoAvailableFlag is off but UndoAvailableFlag is on.
+   // So in either of those cases, (AudioIONotBusyFlag | UndoAvailableFlag | RedoAvailableFlag) mask 
+   // would fail. 
+   // The only way to fix this in the current architecture is to hack in special cases for RedoAvailableFlag
+   // in AudacityProject::UpdateMenus() (ugly) and CommandManager::HandleCommandEntry() (*really* ugly -- 
+   // shouldn't know about particular command names and flags).
+   // Here's the hack that would be necessary in AudacityProject::UpdateMenus(), if somebody decides to do it:
+   //    // Because EnableUsingFlags requires all the flag bits match the corresponding mask bits, 
+   //    // "UndoHistory" specifies only AudioIONotBusyFlag | UndoAvailableFlag, because that 
+   //    // covers the majority of cases where it should be enabled.
+   //    // If history is not empty but we've Undone the whole stack, we also want to enable, 
+   //    // to show the Redo's on stack.
+   //    // "UndoHistory" might already be enabled, but add this check for RedoAvailableFlag.
+   //    if (flags & RedoAvailableFlag)
+   //       mCommandManager.Enable(wxT("UndoHistory"), true);
+   // So for now, enable the command regardless of stack. It will just show empty sometimes. 
+   // FOR REDESIGN, clearly there are some limitations with the flags/mask bitmaps.
    c->AddItem(wxT("UndoHistory"), _("&History..."), FN(OnHistory),
-              AudioIONotBusyFlag | UndoAvailableFlag,
-              AudioIONotBusyFlag | UndoAvailableFlag);
+              AudioIONotBusyFlag,
+              AudioIONotBusyFlag);
 
    c->AddItem(wxT("Karaoke"), _("&Karaoke..."), FN(OnKaraoke), LabelTracksExistFlag, LabelTracksExistFlag); 
    c->AddItem(wxT("MixerBoard"), _("&Mixer Board..."), FN(OnMixerBoard), WaveTracksExistFlag, WaveTracksExistFlag);