My wife/s iphone 3G has been giving us 2 years of faithful service now and suddenly the GPS is very inaccurate. So much so that Navigon's GPS accuracy is so bad it won't route and the Maps app is about a mile or more off. I've read all of the blogs and did everything possible to fix it. (yes, wifi is off, yes, we tried to get it to "find itself" for about 20 minutes in our back yard with the auto lock off, and yes, we reset location warnings and reset network settings). We talked to both applecare and went to the genius bar and they reset the phone and then we came home and synced it as a new iphone, not restoring from a backup in case that file was corrupted as well, and the problem still exists. Can a GPS just go bad in an iphone?