I'm relatively new to this so may be wrong answer, but in loading up the new software / maps etc, I found 2 ways of locking up the device: TomTom home was one the cause of the problem... it recognised i had SE Navcore and locked the device... reloading the software cured the problem. 2nd time was caused by trying to copy across favourites... mapsettings.cfg - after deleted this it worked fine again