I'm having trouble with GPS on my iPhone. It's a 3GS running 4.1. Basically, it's not picking up a signal. I've tried the obvious as in checking the settings for Location Services, I've tried outdoors in a wide open space and I've also restored the iPhone in case it was a software glitch. I've put my phone next to my mates' phone and his works fine. Mine just won't pick up a signal on the Maps application or any other app that uses GPS such as RunKeeper, MotionX or CoPilot. It might be worth mentioning that I nolonger get the message "xxx would like to know your location; Allow/Don't allow". I jailbroke it a couple of weeks ago but because it stopped my AV cable working I pushed the original Apple 4.1 version back on to it and the AV lead works. GPS doesn't. Can anyone shed some light on what I need to do please?