Anyone else had their system lockup on them? I took a trip to Ludlow today for a look around. Pressed the map button on the Nav after I set off and it remained stuck in the startup nav address screen. In fact, nothing worked except the volume control on the unit and the MFSW. All I could do was vary the volume of the radio station I was tuned to. I stopped and removed the key for 30 seconds or so and restarted it only to find it came back instantly to the nav address screen without even going through the startup MMI screen. I pondered the possibility that I'd need to pull its fuse as I wandered around Ludlow. Seemed to me it must have a live feed which was stopping it being fully reset. When I got back to the car it worked fine so just needed a long power-off. Anyone else had this problem?