[IOS} Build crashes on device

We have a problem running the build on any Ios device. Here is our current situation;
Even the simplest Unity project (a box in an empty project) crashes while loading.
The game crashes back to the Iphone screen during the splashpage of Unity (We are not using a custom splashscreen).

Here’s our setup

  • Unity 3.5 on the Mac Book Pro with intel chipset, running the latest Lion OS X.
  • X Code 4.3 installed
  • Project build runs properly on IOS Simulator
  • We are using the latest IOS SDK(5.1)
  • We tried every export setting (Iphone, Ipad, Universal, IOS 3.1.3, IOS 4, IOS 4.2, IOS 5.0, Bundel Identifiers)
  • X Code Project using a single view application (Hello World) build and run properly

Is any version (wrong Unity version or wrong Xcode) causing this problem? If not does anyone knows how to fix this problem and what is causing it?

I think there’s a problem with iOS 5.1 + last Unity… Cause if I try to install my last project on 5.0 it works perfectly, while with 5.1 it works only after the second time I start it. So I really hope that Unity 3.5.1 can solve that.