I've done some reorganizing of my project recently and now I'm not seeing my tab bar controller, but its first view controller's view is appearing.  Here's a breakdown of everything that happens prior to the problem.
App Delegate loads FirstViewController with nib.  FirstViewController loads the application data from my server and then presents MainViewController with a modal transition.  MainViewController is where the UITabBarController is supposed to be appearing.  It's a very simple class.
The .h
@interface MainViewController : UIViewController <UITabBarControllerDelegate> {
    IBOutlet UITabBarController *tabBarController;
}
@property (nonatomic, retain) UITabBarController *tabBarController;
@end
The .m
@implementation MainViewController
@synthesize tabBarController;
- (void)viewDidLoad {
NSLog(@"MainViewController viewDidLoad");
//set tab bar controller delegate to self
tabBarController.delegate = self;
// home view
HomeViewController *home = [[HomeViewController alloc] initWithTab];
// menu view 
MenuViewController *menu = [[MenuViewController alloc] initWithTab];
// special offers view 
SpecialOffersViewController *so = [[SpecialOffersViewController alloc] initWithTab];
// events view 
EventsViewController *events = [[EventsViewController alloc] initWithTab];
// info view 
InfoViewController *info = [[InfoViewController alloc] initWithTab];
//populate the tab bar controller with view controllers
NSArray *controllers = [NSArray arrayWithObjects:home, menu, so, events, info, nil];
tabBarController.viewControllers = controllers;
//release view controllers
[home release];
[menu release];
[so release];
[events release];
[info release];
[controllers release];
//add tab bar controller to view
[self.view addSubview:tabBarController.view];
[super viewDidLoad];
}
and here's the bit from FirstViewController that modally presents the MainViewController...
MainViewController *controller = [[MainViewController alloc] initWithNibName:@"MainViewController" bundle:nil];
    controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:controller animated:YES];
    [controller release];
I'm not getting any compiler errors or warnings and the app runs swell... no crashing.  It just isn't showing the darned TabBar, and it used to when I was creating it on my AppDelegate.  I checked everything in my NIB and my outlets seem to be hooked up ok.  I have no idea what's happened.  Help!