Problems Reading and Writing Files on the iPhone?

If you're having problems reading or writing data using the beta iPhone SDK, you should head over to the iPhone Dev Site at Apple, and download the SQLiteBooks sample code they just posted. There's a workaround in the App Delegate of that project for the problem. 

I can't give details because of the NDA, but if you're trying to do any file reads or writes, or to use SQLite, you should check out the new sample code to find out how to get those working.