My iPhone app was launching just fine in the Simulator until I went to the executable (under Executables in the Groups and Files pane), did Get Info, and in the Arguments dialog, defined the environment variable NSZombieEnabled = YES. I did this after watching your memory management movie. I also accidentally created two empty arguments to be passed on launch (top of Arguments pane - clicked wrong plus sign). I deleted the arguments and deleted the environment var, but I’m still getting “exit with status 5” upon build and go. Curiously, I can then launch the app again from the simulator and it launches OK.