ios 7 view with transparent content overlaps previous view

Question

Recently I updated my xcode project to work with iOS 7, but i faced a big problem. Because my whole application has only one background image (UIImageView added to key window) and all views are transparent, I face a problem when pushing UIViewController, because pushed view controller overlaps previous view (you can see it in the picture here: http://grab.by/qp0k). I can predict that this is because in iOS 7 push transition has been changed, because now it slides half a screen. Maybe anyone knows how to fix this issue?

This is how I set my key windows

  self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
 UIImageView *background = [[UIImageView alloc]initWithFrame:[[UIScreen mainScreen] bounds]];
 background.image = [UIImage imageNamed:@"background.png"]; 
UINavigationController *navi = [[UINavigationController alloc]initWithRootViewController:self.viewController];
self.window.rootViewContro‌​ller = navi;
 [self.window makeKeyAndVisible];

Afterwards when user clicks on "start workout" button I push my next view as always:

workoutView *w = [[workoutView alloc]initWithNibName:@"workoutView" bundle:nil];
        [self.navigationController pushViewController:w animated:YES];

Answer 1

I did this.

-(void)viewWillDisappear:(BOOL)animated{
    [super viewWillDisappear:animated];
    [self.view setAlpha:0];
}

Do not forget re set alpha when come back.

- (void) viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
    [self.view setAlpha:1];
}