I have discovered that my jailbroken iPhone 3GS running 4.0.1 is running into a problem whenever i use any GPS program (TOMTOM, Magellan, Navigon). The GPS program runs fine for about 3-4 minutes, and then the iPhone will automatically reboot... I am not sure how to fix it. I wanted to restore the iOS, but I dont know how to jailbreak it again since I am not sure how to restore with 4.0.1 and not 4.1......