Ok, I made a test application and tried to delete the target of the iPad ... didn't work. Then, since there were two MainWindow.xib files, I realized that something special was done in the Resources-iPad folder. I moved all the files into it to another group and deleted the “Resources-iPad” folder. This allows you to select "Upgrade Current Target for iPad." I ran it again, but selected Universal Application, and then transferred the previous Resource-iPad residents back to their original home.
Repeat:
- Move files in the iPad Resources group to another location
- Delete the iPad Resources group and iPad target.
- Select iPhone Target and go to Project => Update Current Target for iPad
- Select Universal App
- iPad "-iPad"