I had the identical problem with my Nav screen freeze as yours did. The first time it happened I cycled the key and that fixed it. It happened a couple of more times so I reported it to the dealer they put it in my service history to be addressed at a future date. Then one weekend (I think in September or so) it froze for three days, nothing would unlock it so I figured I'd bring in the bike in the winter. Couple of days later, system worked fine without doing anything to it and it has operated fine since. Since I've been riding so much this winter and the screen and Nav have been fine I'm going to leave it alone unless something happens again. Lots of 2012 owners have been reporting rebooting issues with the Nav, that has happened to me twice. The Nav has to come out of the bike and sent out to have new firmware installed.