Odd issues with screen saver/power save

To be able to leave my system on at night, I need to use the power save mode on my flatscreen. That way, it will blank, then turn itself off after 30 minutes. Recently, I have noticed that it doesn't turn itself off anymore. Instead it only does the screen saver. Where should I start looking to see why it is not doing power save? (I don't remember any patches that may have affected this.) thanks eric