iOS Bug? - Have to delete app and reinstall every time I want to test it

Hello.

When I run an app it is displayed. However if I either:

  1. Rerun the app through XCode, or

  2. Exist the app and rerun it from device/simulator

I get a black screen.

Deleting the app from the device/simulator and rerunning from XCode produces no problems (no need to do a clean).

Anyone know what might be wrong? Any tips are welcomed.

Better upgrade xcode to 4.5 and the latest ios sdk(6.0).
Hope that helps