- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    navigationController = [[AGIMainNewsViewController controller] retain];
    mainController = [((AGIMainNewsViewController*)[navigationController topViewController]) retain];

    // Add the view controller's view to the window and display.
    [self.window addSubview:navigationController.view];
    [self.window makeKeyAndVisible];
}

my it's [AGIMainNewsViewController controller]

+ (UINavigationController *) controller {
    UINavigationController *a = [[[UINavigationController alloc] initWithRootViewController:
                                  [[[AGIMainNewsViewController alloc] init] autorelease]] autorelease];
    a.navigationBar.tintColor = [UIColor colorWithRed:0.071 green:0.114 blue:0.247 alpha:1.000];
    a.navigationBar.hidden = YES;
    return a;
}

while in my main top view controller AGIMainNewsViewController i've


    [[self navigationController]setNavigationBarHidden:NO animated:NO];

but it does not work