That's definetly not normal, it was probably a glitch.
- It was a glitch, just try again
- It was a hack (probably not, since you don't have an Action Replay)
- It was an used game, and the player before you used Action Replay
- You didn't take good care of your game
- It was an used game, and the user before you didn't take good care of it
Hope This Helped :D