There are a few things you can do, to prevent your steps from being accidentally erased.
1) Pressing down the RESET button for 3 seconds will reset counts to zero
Sometimes this happens inadvertently if you were to lean against something or if the pedometer is pressed up against the wall of your pocket.
To Prevent, try placing your pedometer in a location where it isn't as likely to happen. Or keep the pedometer on the clock screen where it won't make a difference.
2) Pressing down on the MODE button while on the Step screen will Activate or Deactivate the Step sensor. If the step sensor is deactivated, the pedometer display will work but no steps will be counted.
Click for directions on re-activating the step sensor.
3) Set clock to correct time AM/PM or Military time. The clock on your pedometer is programmed to reset all counts to zero at midnight daily. If the clock were set incorrectly this could take place during the day causing you to lose your steps. Click for directions on how to set your clock.