iPhone – Replacing rootview in navigation controller

From UINavigationController reference:

This method (popViewControllerAnimated:) removes the top view controller from the stack and makes
the new top of the stack the active view controller. If the view
controller at the top of the stack is the root view controller, this
method does nothing. In other words, you cannot pop the last item on
the stack.

You can try the setViewControllers:animated: method instead.

- (void) goNext {

    NextViewController* nextWindow = [[[NextViewController alloc] initWithNibName:@"NextView" bundle:nil] autorelease];
    [self.navigationController setViewControllers:[NSArray arrayWithObject:detailViewController] animated:YES];
}