I have a tom tom one xl v3. I have upgraded to map 875.3675 and I have also upgraded the navcore to multiple different versions however I always get the same problem that after using the tom tom for a while the sound just stops. This can happen after 15 mins or an hour but it always happens. When this does happen when i try to turn the device off it will automatically reboot instead and usual works correctly again for a while. I have tried 5 or 6 different 9.xx version of navcore and have now tried to use version 8.56 which I have not fully tested but the options for camera alerts are not showing with this version.