I recently checked out this thread to figure out whether the downgrade from ios 7 beta to 6.1.4 was even possible on my iphone 5, since I recieved a replacement phone and need to send the old one to apple. I reset the iphone to factory settings while it was still on ios 7 to simply delete all the content, this is where I got an error message from itunes saying that "This device is not registered under the Apple Developer program" and thus could not be activated. At this point I was thinking I was SOL (I am not registered as a developer), but figured i would try some different methods. Using Redsn0w 0.9.15b3, I was able to manually select the 6.1.4 firmware without having to go through Itunes, worked first try. I figured after so much arguing and stress over wondering if it is possible to get an iphone warrantied that is on ios 7 I would share this method. This is my first post on the site but ive frequently been on here observing. hope this helps someone in the warranty process