My son was blocked last night due to exceeding his total hours per day on the computer. His account is set to 4 hours per day and based on the Norton usage log, the alarm was trigged after just 2 hours.
I think I may have something setup wrong or there is a little problem with the Norton monitoring.
One of the possibilities is that the kid has reached the time in the "Range of hours blocking XXX from using the computer" under Settings -> Time after two hours. Please check the Time Settings or send us the screen shots, so we can check for you.