With universal app I had iPad splash screen showing up in simulator but not on device. The iPad would instead show the Default.png splash for the iPhone. The Default-Landscape.png and Default-Portrait.png files existing, so wth? Resolution should be correct since I created the screen captures using Window | Organizer | Screenshots and used 'Save as Default Image' for the iPad, then just renamed it.
Turns out (from my one app anyways) the two iPad screen shots have to be moved to the Resources-iPad directory. Then it all works fine. Seems obvious now, but in case anyone else has lost sleep over this... -Larry