I have official Apple tethering enabled by changing the carrier file (NOT jailbreak). I am NOT updating the OS to 3.1.3 because I don't want to lose it. How do I go about backing up this OS along with the hacked carrier file so I can do a "clean" reinstall? The phone is running a bit slow so I want o do a complete wipe to clear all the crap in memory. Will I be able to reinstall from backup with the hack untouched?