I purchased a used Pokemon Ruby with no manual. I have played it and several times and saved the game file. When I do a game reset(select+start+A+B) the game resets and loads the saved file. However, everytime I power off after saving, and restart the game, a message appears upon loading the game "The save file has been deleted". I am playing the GBA cartridge on my Nintendo DS. Does anyone know why this happens and how to avoid the deletion of the saved file?