I know there are already a bunch of threads about this problem. But I've tried everything. If I try to start a downloaded app, the screen will go black like its about to start, and then I'll get sent back to the menu. When this first started I would simply delete and redownload one app, and that would fix them all. But now its seems I have to delete them all to fix it. I've done the hard reset, and I've done the restore in iTunes, and it still does it. And its really getting annoying. Any help?