How do I load a localized tip?

I have localized my nib files, I have English and Polish versions:

alt text http://img695.imageshack.us/img695/70/postitappdelegatemtwitt.png

In my code, I load nib:

newPostUIViewController = [[NewPostUIViewController alloc] initWithNibName:@"NewPostView" bundle:nil]; 

      

        
        
        
      

    

Unfortunately, when I run my application in Polish mode, I can still see the English version of the user interface. Do I need to do something to get my app to display the Polish version of the UI?