John - best bet is to do what I said in my last post #680. If you press the round button and the power button at the same time and send it off to the guys they can tell if the coordinates being received from the inbuilt GPS are accurate or not. (assuming the lat long is being displayed when you take the capture)
I went down to Flinders a couple of weekends back and didn't experience any issues to I doubt there was a map issue or anything as the guys that go there would have said something.