Having a 5 year old GPS, I've noticed something interesting. 2 years after I got my Nuvi, and my GPS kept telling me that my maps were more than 2 years old, I noticed my nuvi 360 doing something peculiar. A third of the time, it would just fail to lock on to a GPS signal no matter what I did, until I restarted it. After I updated the maps and the software, the problem went away.
2 years after that I'm noticing the exact same thing happen. It wouldn't be so bad if they weren't charging for these map updates.