Windows Vista Baffled with power management

I have made some progress in finding out what is causing my problem: If I am running on battery power and I let it sit until it hits the time where it is supposed to sleep it does fine; the screen turns off, the hard drive powers down, and the power button blinks indicating it is in sleep mode. In contrast, if I'm running with it plugged in to a surge protector, and it hits the time limit were it's supposed to sleep only the screen turns off and the power light is not blinking indicating to me that it is not really asleep, also the hard drive does not power down. There has to be something there that is only present when it's plugged in, and whatever that is is probably causing the problem. Could it be the surge protector? Any help would be appreciated.

 

yea I know that, its the same with vista. two separate settings. its just that the on ac power options don't seem to work right

 

It's a brand new computer with an outdated video driver. Had to download current driver and it still didn't work. Since it slept fine on battery power, I decided to set plugged in settings like battery settings and it finally worked. By eliminating "advanced settings" one by one, I found the culprit under "multi-media...when sharing ". It's called "prevent idling to sleep" which is the default setting. I changed it to "allow to sleep" which I think should be the default setting. Lots of time spent on this just to save a little energy. It was worth it though cause my notebook rocks now.