I started with an iPhone-only app, which worked fine on both iPhone and iPad (it ran in a small, iPhone-sized window on the iPad... which was fine). Then I selected iPhone/iPad for the Target Device Family, and created a blank MyViewController~ipad.xib. Then I decided to revert the app to its former self, and I deleted the ~ipad.xib and set the Target Device Family back to iPhone only.
Now, my view is displayed as before on the iPad, but I cannot interact with the view. Everything works properly on the iPhone, but on the iPad, it seems like my buttons are not linked to their corresponding actions. But, there is only on nib now, so obviously those buttons are linked, because they work on the iPhone.
Per @wrights suggestion, I deleted all of the simulator files and clean the project again. Then I got a new error: *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Could not load NIB in bundle: 'NSBundle </Users/hap/Library/Application Support/iPhone Simulator/5.1/Applications/83BECBAA-2558-4927-9347-FAC972168299/WxT.app> (loaded)' with name 'MainWindow-iPad''
The app just crashes at this point.
I'd like to get the app working properly on the iPad, as it was before... with just the single nib. Any help would be very much appreciated!