My sons are not logged off the computer when their time expires. The simply ignore the message and keep on playing flash games in the browser.
As you can see by the screen shot he is still logged in and you have the message stating that he reached his time limit at 6:46 PM. The computer clock shows 7:06 PM.
This has always been this way.
No he is not an Administrator.
No he doesn't know how to get into any of my accounts.
OS is Vista.
I was logged in via a remote desktop session.