What's going on?
First of all: remove the application from your device manually. Installing new version on top of old using Xcode "Build and Debug" (Command-Return) doesn't always work. Mostly yes, but not always.
Second: debug all possible hardware setups in simulator. It wasn't too obvious how to do it, so here's some tips:
- Use Xcode top left corner popup to select iOS version. With current SDK I can select iPhone 4.0, iPhone 4.1, iPhone 4.2 or iPad 4.2. Choose one and do "Build and Debug" to open simulator.
- Use simulator menu Hardware - Device to select hardware. With current simulator I can select iPad, iPhone, iPhone (retina). Next time you launch simulator from Xcode, it will use the selection.