Hi, I have set my power management setting to shut my monitor off after 5 minutes... however sometimes it's not working and my computer will sit for hours without it shutting off, and yet sometimes it will work. At first I thought it was a Desktop Sidebar causing this, but now I think it's something else. Here is a screen of my processes running
Use the proccess of elimination. Set it to shut off after 1 min, if it doesn't end a process. After a min, end another til youfind it.