为什么在applicationDidFinishLaunchingWithOptions中未显示模态视图控制器？

Question

My application presents a modal view controller (a passcode entry form) whenever the application is run. I present the view controller in two application delegate methods:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [self.window.rootViewController presentModalViewController:self.passcodeViewController animated:NO];
    //...
    return YES;
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
    if (!self.passcodeViewController.view.window) {
        [self.window.rootViewController presentModalViewController:self.passcodeViewController animated:NO];
    }
}

The call to present the modal view controller in the application:didFinishLaunchingWithOptions: method does not present the view controller, where as the call in applicationDidBecomeActive: does. Why is this?

EDIT : I wanted to mention, per the comments below, that I'm using a Storyboard and that self.window.rootViewController does indeed point to an object (basically, it's not nil)

Answer 1

From the UIApplicationDelegate Protocol Manual Reference:

It is called after your application has been launched and its main nib file has been loaded. At the time this method is called, your application is in the inactive state.