I was working on upgrading a clients app today to use Apple’s retina display when I ran into this problem that had me stumped for a couple of hours. The application compiled OK but when it installed and launched in the simulator after showing the default.png splash image it went completely black. Huh? The app apparently had worked fine on the original developers computer and after fixing a few compiler warnings that I thought may be the problem I stumbled upon this thread and thankfully the solution.

Solution:
Apparently this can happen after installing some iOS 3.0 and 4.0 updates. Some of these major updates seem to change the MainWindow.xib file in your project so that the checkbox in Interface Builder > Attributes marked “Visible at launch” is de-selected. Heaven knows why, but I turned it back on and voila it all worked. I thought posting this may help someone else someday a few hours of pain chasing your tail. If anyone knows whether Apple did this for a good reason please post a reply – I would love to know why!?