I can be sitting still and the GPS for running turns on. While running, I don't even have to flex my wrist and it flips from stop to start for about 20 seconds and then just stops. At each mile marker it decides I am done and the GPS stops. It's about 2 months, this started about a month ago. Third garmin, first HUGE disappointment. The 'Key' is in a horrible spot. Garmin can do better. Any ideas?