UITabbar + ModalViewController

I have a viewController that I am presenting as modalViewController in my ParentViewController. The parentViewController has a UITab bar with 2 tabs. When I present the ChildCiewController as modalViewController, there is blank space the size of UITab bar at the bottom of the ChildViewController.view. How to get rid of it?

InAppPurchaseViewController *purchaseViewController = [[InAppPurchaseViewController alloc] initWithNibName:@"InAppPurchaseViewController" bundle:nil];              


purchaseViewController.modalTransitionStyle = UIModalTransitionStyleCro开发者_Go百科ssDissolve;                      

[self presentModalViewController:purchaseViewController animated:YES];

[purchaseViewController release];

Thanks in Advance

Be sure that purchaseViewController.view.frame is correct (0, 0, 320, 480).

Test with CGRect r = purchaseViewController.view.frame; NSLog(@"frame is: %d - %d - %d -%d", r.origin.x, r.origin.y, r.size.width, r.size.height)

Hope this helps