What you are attempting to use is something called "hybrid sleep" where it sleeps for a certain time period and then wakes back up when that time expires and goes into hibernation. This is only available on Vista (Service pack needed) and windows 7.
ok, what would be my best option to save my battery since I am using xp? Should I just have it to hibernate on power off? Oh, I am using a m2 power supply. I am using jumper 1 setting. If I set it to stand by, will the m2 shut off power completely after a given time to save my battery?