IF you are talking about PTAT feature , you can turn the network off for that day, but you would have to go back and turn it back on for the day you want it to record. So in my PTAT , I turn off Saturdays entirely since they don't show anything but Sports and reruns on networks. I even turned off Sundays and set up just timers for the shows I want to watch on CBS and ABC. Since sports causes over-runs on CBS , I setup the timers with 90 minutes extra for The Good Wife and The Mentalist.
IF you go into the locks or parental controls menu, you have to make sure that once you select the channels you want to lock out, that you hit on the far right the HIDE SELECTED CHANNELS ? and say YES. That and you have to hit SAVE and then once you leave that application you have to hit SAVE again and of course you have to have a password code in the system and it should lock out all the channels you want. I do this on my joeys and hoppers and it works for me.