iOS development tip: Xcode 4.4.1 will open Xcode 4.5 projects fine, but empty the intermediates folder first, lest build confusion ensue.
— Gregg Seelhoff (@GreggSeelhoff) November 14, 2012
Details: I dropped the iOS Deployment Target to 3.2, and the project built (seemingly) properly for all iPads, but Xcode 4.4.1 refused to actually send the app to the device. It ran the existing (older) version on the device the first time, and when that was deleted manually, it threw error messages about not being able to find the file. (!) Cleaning the project did not seem to work, but erasing the intermediates folder did the trick.