Hi, first you need to find some way to shut the monitors off with a normal desktop shortcut. Try LCDoff.exe from here: http://kev009.com/wp/projects/lcdoff/
Another one: http://www.redmondpie.com/turn-off-your-notebook-lcd-with-one-click/
If that doesn't work, let me know how you tried NirSoft's utility. Did you use "nircmd.exe monitor off" and how did you run this? In a shortcut or batch file or what? If you double clicked on it with a mouse, then maybe the mouse movement woke the monitors back up. Try highlighting a shortcut to it and pressing Enter on it to see if that works. Or if it's in a batch file, you could add a short delay before running the command and this might prevent the mouse from waking the monitors back up.
Once...