My GO910 TomTom has "locked" on to Portugal and the USA. The TomTom has been to Portugal in recent months but NOT the USA. Normally when selecting an address or postcode (e.g. when re-setting Home), a drop-down menu appears in the top right-hand corner of the screen with a list of countries This is not happening now. Anyone know why? I have tried the reset twice but no change, also syncing with my PC, no change. Any ideas please?