I've had my doubts for a few weeks of the proper functioning of my GPS so today I decided to do a little test. I put my wifes 3G running CoPilot in the car alongside my 3GS running Navigon. The 3G never dropped signal once on a 1hr drive. The Navigon on the 3GS was dropping signal every few mins. So then I tried running CoPilot on mine. While it wasn't losing signal to the extent of Navigon, it was clearly struggling - it kep re-evaluating the route and going around roundabouts it was almost like it didn't know which was we were facing where in contrast it was working great on the 3G knowing exactly where we were at all times. I then tried one last thing - going back to Navigon, I reset my network settings which I'd read can help? Fot he last 10 mins Navigon didn't drop its signal once but having it working for 10 mins doesn't exactly inspire confidence. Is all this normal, to have such widely different experiences between devices? Are there any other tips and tricks to test? Edit: Both phones running 3.0 but the 3GS is jailbroken where as the 3G isn't if that makes a difference?