I just bought a Mavic M-Tech 9 computer. After setting it up and calibrating, I put it in the cradle and as soon as the magnet passes the sensor, it restes itself!! It goes back to the SEL screen and the calibration goes back to default. It remains like that until you set it again. Once you move off again, it resets AGAIN!!!
I took it back to the shop to swap for a new meter, but this one behaves in just the same way.