iphone build does not work

I have a unity project that i want to run on iphone 4. If i am testing from XCode everything is working fine, but if i stop the XCode project, disconnect the phone and try to run again the project doesn’t work. (the unity begin screen appears, is loading for 2-3 seconds and that’s it.)

In unity i am building without any of the check boxes checked (SymLink, etc). In XCode i run the project for release and not debug.
I disabled all the script that i am using and the problem remains.
any idea would be great ?

Thanks in advance for your answer.

Try deleting the app from your iPhone, rebuild your project with a new name and run again. I had the same issue several times and this seemed to do the trick. Hope this helps.

My model was the problem. I change some things in the model and now it’s ok. I think i had to much vertices in the scene.
Thanks a lot. Problem solved.