Hi, I have an iPhone 3G running 3.1.3. When 4.1 was available, I updated it and tested GPS right away (without WiFi!). It worked perfectly! It was very very accurate. Because there is still no decent jailbreak for 4.1, I downgraded again to 3.1.3. I tested GPS again (with WiFi because without it doesn't work), and it was off by 2 - 3 km (around 1.5 miles). GPS Status (the app) reported "Good fix" on 4.1 and "Bad fix" on 3.1.3 at the exact same spot (my room). Okay, I know this is indoors, but why does 4.1 get a good fix and 3.1.3 don't? It's not because it's jailbroken, because I tested it before I jailbroke. I will now try 3.1.2. See if that helps. 4.0(.1) is not an option, because it's too slow. Hoping for help Edit: Forgot to mention that on 3.1.3 Navigon/TomTom doesn't work at all (no GPS fix). Didn't test on 4.1 though.