Minecraft appears to disable NOF service

Another in the continuing conflicts with NOF and Minecraft.

 

My son is an addict and am doing my best to limit his time to about an hour a day. He does not have administrator rights nor does he have the NOF password.

 

At some point during his sessions it appears that the NOF service shuts down. When I look on my account on the PC, I see two or three of the NOF "paw" icons with red X's on them (rather than the normal non-X version when NOF is running properly). When I click on those, they disappear. NOF itself is no longer running and when I open up the task manager I see that the NOF service (not program) is stopped. If I right click it to restart, everything starts up fine (the other option is a full reboot, which is a pain).

 

I do not get an email notification that the service has shut down, which tells me that it isn't being shut down from within the NOF control panel but by some external process.

 

System is Windows 7 Home Premium, current version of Norton Internet Security and Norton Online Family. No additional Windows security (other than account passwords) is running. He accesses Minecraft either through a web browser (Chrome) or the downloadable Java (I'm assuming) module. I haven't sat down with the game to see if I can duplicate the issue, so I don't know if it is shutting down NOF once the time limit is up or at some other point.

 

Thanks.