MSFT and other programs update and things change. You get to go back through any and all control panels to change this. Sometimes, with machines that don't reboot but sleep, you have to do a true reboot.
I don't know what is going on with the OS, or whatever may be causing the disfunction but here is a description:
Lately when my laptop is sitting idle for about twenty minutes or so it logs out and goes to the password screen, as if I had put it to sleep or hibernated it. But it just goes straight to the password screen. I have no settings to sleep the laptop after a certain amount of time or anything that would turn off the display or any other setting like that. And it just started happening this week, I have a sony vaio, and it is running windows 7 64 bit ultimate, I have no idea what setting I could have accidentally changed to make this occur and I wanted to see if anyone else has had or heard of this strange problem?