IB - Can't get view to display for navcontroller

[dlg_noob]

I'm so new it's not even funny. But I created a simple view application, and I've since added the tabbar and a navigation controller for each tab button which I've successfully gotten to display an empty UIViewController.

However, now I'm trying to connect the UIViewController to an identically named NIB file. Here's what I've done so far:

1.) In the nib file I've created a simple button and I've linked the view to the file's owner which in turn references the original viewcontroller as it's class.
2.) The class viewController is setup with an IBOutlet UIButton as well.
3.) In the app delegate file I'm loading this by:

searchViewController = [[SearchViewController alloc] initWithNibName:@"SearchViewController" bundle: nil];
searchViewController.title = @"Search";
UINavigationController *searchNavController = [[UINavigationController alloc] init];
[searchNavController pushViewController: searchViewController animated: YES];
[searchViewController release];

tabBarController.viewControllers = [NSArray arrayWithObjects: searchNavController, FavoritesNavController, nil];

The problem is that I was able to load the UIViewController perfectly fine until I started trying to load it with a NIB file. At the moment I have an empty space in the tab bar where search went before (the space is actually allocated) and there's a blank view.

What could I be doing wrong? Any help is GREATLY appreciated!