I have just bought a used MX5 Mazda which is fitted with an NVA SD8110. SatNav shows only "No Maps Found". TomTom Home shows that Europe Western Zone is on the SD card. I deleted the Europe data which was on the card when I first checked it and replaced it with Europe Western Zone as forums seemed to suggest that the Data might have been corrupt. The person who sold the car said that the problem first presented itself when the car battery was left flat for a few days. When the “No maps found” issue presented itself to the previous owner, TomTom sent him a 2nd SD card which I now have, however this did not help with the problem. Is there any way I can check to know if the problem is with the data on the SD card or maybe it's the unit itself. All other features work fine, radio, CD, Aux, etc.