Laura, I have a similar problem if I travel a long distance, a few hundred miles or so, and then turn on my Garmin. It gets confused when my last position was really far away, but it eventually figures things out in a few minutes. It took about 20 minutes to realize it was in Hawaii.
Regardless of how much we warn people, many will just not put in the effort to learn the basic skills or carry a real map. They can get away with that on the Whitney main trail, but...
