text disappear when setting image to navBar

Question

Im showing an image a nav bar, but the title has disappear, why?

how to fix it?

 - (void)viewDidLoad {
[super viewDidLoad];

UIImage *image = [UIImage imageNamed: @"navbar.png"];

 UIImageView *imageView = [[UIImageView alloc]initWithImage:image];
self.navigationItem.titleView=imageView;
[imageView release];
 // self.title = @"Bio"; 
self.navigationItem.title = @"Bio";
}

Thanks a lot!