+- (void) didReceiveMemoryWarning {
+ [super didReceiveMemoryWarning];
+
+ // presenting a UINavigationController on 2.x does not update its transitionView
+ // it thereby will not allow its topViewController to be unloaded by memory pressure
+ if (kCFCoreFoundationVersionNumber < kCFCoreFoundationVersionNumber_iPhoneOS_3_0) {
+ UIViewController *selected([self selectedViewController]);
+ for (UINavigationController *controller in [self viewControllers])
+ if (controller != selected)
+ if (UIViewController *top = [controller topViewController])
+ [top unloadView];
+ }
+}
+