Police registration form

Hi, I have just re-enter china after a 6 days trip abroad, I have a one year residence permit and work permit, my wife is also chinese from shanghai, after 24 hours she went to the police station for me to re-register as I just came back, the policeman said that I did not need to re-register as long as i did not change my adress since i came back or needed a new visa, how accurate do you think this is?