Problem with getting a modalViewController to appear

I've been fighting with this for hours. I've searched around everywhere and just can't seem to find the solution to my problem. I'm pretty sure I'm just lacking some key concepts here.

My AppDelegate (didFinishLaunching) basically sets up my window and invokes RootViewController:

 // create our window
 UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
 [window setBackgroundColor:[UIColor blackColor]];

 // create our rootviewcontroller
 RootViewController *controller = [[开发者_运维问答RootViewController alloc] init];

 // add our rootviewcontroller's view to our window
 [window addSubview:controller.view];

 // controller is now owned by window's view
 [controller release];

 // show us to the world
 [window makeKeyAndVisible];

When I add controller.view as window's subview, my understanding is that RootVC's loadView will automatically get called.

In RootVC loadView, I create a tabBarController, each tab having a navigationController and it's own viewController. All that is working fine.

In RootVC viewDidLoad, I'm checking to see if this is the first time a user is running this app, and if so, I want to throw up a modal welcome screen. This is the part I'm having trouble with.

I'd like to keep as much code out of the RootVC's viewDidLoad method, and ideally would be able to accomplish what I want with this:

WelcomeViewController *welcome = [[WelcomeViewController alloc] init];
[self presentModalViewController:welcome animated:true];
[welcome release]; 

Obviously this isn't working. WelcomeVC's loadView hasn't been run yet because I haven't explicitly set it's view property. I've played around with a bunch of different solutions (welcome.view - [[UIView....], using WelcomeVC's init method to set self.view) but I just can't seem to get that modal to pop up.

How should I accomplish what I'm looking for? What are the best practices, and what's the best solution to keep my code tight and tidy?

I'm stuck, so hopefully your solution will allow me to continue developing my app!

Although the problem is not so simple, the solution is. You have to wait until the main view appears. So check the condition and present your modal view in viewDidAppear method, not in viewDidLoad method.