UITabBarController与ios5和ios6的区别

Question

我已经编写了以下代码来创建UITabBarController

{
    NSMutableArray *arr = [[NSMutableArray alloc]init];
    STPC_AgendaController *agendaController = [[STPC_AgendaController alloc]initWithNibName:@"STPC_AgendaController" bundle:nil];

    STPC_Sponserer *Sponserer = [[STPC_Sponserer alloc]initWithNibName:@"STPC_Sponserer" bundle:nil];
    Sponserer.tabBarItem.title = @"Sponsors";
    STPC_AboutUsViewController  *aboutUs = [[STPC_AboutUsViewController alloc]initWithNibName:@"STPC_AboutUsViewController" bundle:nil];
aboutUs.tabBarItem.title = @"About us";

    UINavigationController *agendaNavigation = [[UINavigationController alloc]
                                                initWithRootViewController:agendaController];

    agendaNavigation.tabBarItem.title = @"Agenda";

    self.navigationController.navigationBarHidden = YES;
    self.tabController = [[UITabBarController alloc]init];
    [arr addObject:agendaNavigation];
    [arr addObject:Sponserer];
    [arr addObject:aboutUs];

    [self.tabController setViewControllers:arr animated:YES];

    [self resignFirstResponder];
    [self.view addSubview:self.tabController.view];
}

然而它在ios5中的表现不同：  

和ios6：  

ios5和ios6的PFA截图。如何创建一个tabbar控制器，使其在ios5和ios6中看起来完全相同？

任何有用的帮助。