I have an integrated Satnav in my Mazda 5. My TomTom Live contract recently expired so I have just paid up and updated the SD Card. However, despite uploading the Quick GPS fix, the car now thinks that it is about 100 miles away from where it actually is. On my way back from work today, I have apparently driven most of the way through the hills, rivers and villages of Wales. I've not be anywhere near Wales.
How has this happened and how can I fix it?