So a while back i did the hack where you change the carrier file to get tethering without having to JB, since then i have gone about updating the firmware and all that normally and figured the tethering hack would be gone, but some how it has remained on my iphone. I just did a restore from backup and still, the tethering option is available. Im unsure how its still there and im hesitant to use it because i don't want to be charged. Any theories?