NOF does not update curfew setting after the child logged in

My child curfew is 6:30PM to 8PM.  He logged on at 6:25PM. He got warnning that he has only 5 minutes.  He was logged off by NOF.  I used another computer to change curfew time to 7PM to 8PM.  But he logged on and still got logged off again by NOF every 2 min or so til past 6:45PM.  He quitted after that.  It seems that NOF does not update the new setting.

 

He has standard user acc with password.

Window is 7

Norton IS 2011