#include <QtGui/QApplication>
#include <QtGui/QPushButton>
#include <QtGui/QMenuBar>
#include <QtGui/QMenu>
#include <QtGui/QAction>

int main(int argc, char** argv)
{
	QApplication app(argc, argv);

	QWidget* widget = new QWidget;
	widget->resize(300,200);

	QMenuBar* menu = new QMenuBar(widget);

	// Populate the menu bar with a menu which is initially hidden.
	QMenu* testMenu = new QMenu("Test");
	menu->addMenu(testMenu);
	testMenu->menuAction()->setVisible(false);

	QAction* testAction = new QAction("Test Action", testMenu);
	testMenu->addAction(testAction);

	// Add a button which shows the menu when pressed
	QPushButton* button = new QPushButton("Show Menu", widget);
	button->setCheckable(true);
	QObject::connect(button, SIGNAL(toggled(bool)), testMenu->menuAction(), SLOT(setVisible(bool)));

	// When the widget is shown, click the button to show the menu.  The 'Test Action' item
	// will be disabled, though it should be enabled.

	// Un-comment this line to show the menu when the window is initially shown.
	// The problem will not occur in this case.

	//button->setChecked(true);

	widget->show();

	return app.exec();
}

--- a/src/gui/kernel/qcocoamenuloader_mac.mm
+++ b/src/gui/kernel/qcocoamenuloader_mac.mm
@@ -268,7 +268,11 @@ QT_USE_NAMESPACE
         || [menuItem action] == @selector(unhideAllApplications:)) {
         return [NSApp validateMenuItem:menuItem];
     } else {
-        return [menuItem isEnabled];
+        if (QAction* action = reinterpret_cast<QAction*>([menuItem tag])) {
+            return action->isEnabled();
+        } else {
+            return [menuItem isEnabled];
+        }
     }
 }