My iPad app needs to store its data in some files. On the simulator, my program can read and write its data files just fine. It stores its data, then I tell it to exit and later when I run the app, it reads that data in just fine. I just tried running the app on an iPad however and it appears that file writing is not happening. Is there some sort of limitation that's imposed on ad hoc apps during testing that doesn't appear in real apps? My app has already been accepted and is being sold so I assume it's just my iPad that has got this problem. Note, I did not update iOS before running the app on the iPad. Thanks.