iPad specific resource suffix doesn't work with storyboards

Question

According to the Apple's Resource Programming Guide you should be able to use device modifiers for any kind of resource file

Here's the quote

You can apply device modifiers to any type of resource file.

However while this seems to work for most resources (images, nibs) I'm running into problems when using it with storyboards.

What I've tried doing is having two storyboards with one of them having the ~ipad suffix attached to it's file name, and trying to load it like the following

  UIStoryboard *mySB = 
       [UIStoryboard storyboardWithName:@"MyStoryboard" bundle:nil];
    myViewController = [sigRequestSB instantiateInitialViewController];

And I'm getting a NSInternalInconsistencyException exception

The strange thing is that I only get this error if I have a storyboard with the ~ipad modifier, if I have only the single storyboard without the modifier it will just load that on the iPad. Further if I detect the what device is running and load the storyboard using the full file name (that is on an iPad attach the "~ipad" to the filename) it works.

Here's the full error

2013-08-29 15:32:44.294 MyApp[18757:c07] * Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle (loaded)' with name 'UIViewController-Cq1-k2-VhC' and directory 'MyStoryboard.storyboardc''