gdgt

If you are still looking for an answer to this question, I have an answer. This exact same problem happened to me, but you have to be willing to jailbreak for a day if you want this fixed. Okay, so first what you'll want to do is jailbreak using redsn0w. If you ware running iOS 4.3 through 4.3.5 just download MT Gestures, and flip the option and you'll be good to go. If you are running iOS 5.0 or above, please keep reading. Secondly, you'll want to add the repository cydia.xsellize.com . It'll warn you about all the illegal stuff (what you're doing is not illegal) and then just hit okay. Once you have that installed, you'll want to install the following programs "iFile", and "Mobile Terminal". Once you have iFile installed and opened navigate to system/library/Core Services and go down to the bottom where you will find SystemVersion.plist. Open that and hit edit. Then change you version to 4.3.1 and you build version to 8G4. Then, reboot your device DO NOT RESPRING, THIS REQUIRES A REBOOT. Once you have that done search Cydia for MT Gestures and find MTG/SS Enable, and be sure to get the one that is made specifically for you device, in your case click iPhone 4. Once you have done that and it's installed, go to setting->general, and tap on orientation lock, and if that doesn't switch it, go to mute (sometimes it's flip-flopped). Once you've done that, if you want be entirely sure that this will not happen again, go the Mobile Terminal and first type in the command su and if it asks you for a password, type in alpine. After that, type in the command dpkg --force-depends -r com.sull.mtgssenableripod4 .This will erase the program, and just double check and make sure that it's still an orientation switch. Once you've done that, just backup, on iCloud or iTunes (whichever you prefer) and then restore once that's done and that should do it! I know how frustrating this is. All this Googling and trial and error took about 10 hours. Again, hope this helps.

-Colin