While I was reading an article on X configuration things, I noticed that there was a part for monitor shutoff/suspend/whatever it does. Here's a paste of the article (found at http://www.linuxorbit.com/modules.ph...icle&artid=493
Have you noticed that if you leave your computer untouched for long enough, the screen will go black? Well the amount of time it takes to go black can be set in the "ServerFlags" section of the configuration file like this:
Option "BlankTime" "15"
The number at the end of the line sets the time in minutes for your screen to blank when X-Windows is idle. By default, this value is 10. You can also set the times for your monitor to go into standby, suspend, or offline with the options "StandbyTime", "SuspendTime", and "Offtime" respectively. Their syntax is just like BlankTime and their default values are 20, 30, and 40. All of the latter three do the same thing on my monitor, but your results may vary. To enable these features if they're not already, just add the Option lines in your "ServerFlags" Seciton.
In your case, you would probably be wise to disable this or to make it a huge number so as to avoid the blank monitor syndrome. Hope this helps.