Whenever I leave my Pi for too long, especially overnight, it shuts down rather than goes to sleep. Or sleep mode makes it shut down. I see the power LED off. I move the mouse and type on the keyboard and then it wakes up! Only problem is it boots from the beginning... it doesn't leave me where I last left the Pi on the desktop.
What's going on? Is there a setting so that sleep mode is not shut off?
I'm using the Debian Linux distribution from Raspberry Pi's download page.
UPDATE: When the Pi is in sleep mode, the monitor is blank but still on and the LEDs are all off. However, when I choose Log off->Shut down from X in the Debian operating system, the monitor reports there's no longer an HDMI connection and goes into that semi-sleep mode itself when a computer is unplugged. And the Power LED on the Pi remains lit red. Finally, of course, moving the mouse or typing on the keyboard does NOT wake up the computer after I've powered down.