Monitor doesn't go to sleep; cursor in middle of screen

I have Windows 8 x64 Professional. I customized my power plan (High Performance) so that the monitor sleeps after 5 minutes of inactivity. However, the monitor doesn't actually sleep. The LCD's colors turn to black, instead of the panel/back-light turning off. The mouse cursor also stays idle in the center of the screen. In the advanced power options, I've made sure sleep happens after 5...