I have a UIViewController with this method:

```
-(void)prepareToShowVault {

...

UINavigationController *passcodeNavigationController = [[UINavigationController alloc] initWithRootViewController:passcodeViewController];
        [self.navigationController presentModalViewController:passcodeNavigationController animated:YES];
        [passcodeViewController release];
        [passcodeNavigationController release];
}

```

When called from another method in this UIViewController, it works just fine. But when called from another UIViewController, this method fires but the code doesn't display a new modalViewController, presumably because the UIViewController with the above method isn't active. How can i make this work?