Hi armysgt1,
Have you tried reactivating the power settings (i.e. going to Power Options, selecting Turn off monitor-->Never, clicking Apply and then selecting Turn off monitor-->After 10 minutes and clicking Apply)??? I know it sounds simple, but that might do the trick as it's being applied to the new hardware.
If not, I would look at what processes are starting up via msconfig (Start-->Run-->type 'msconfig', <enter> -->Startup) and look for anything that may be installed with the graphics card software and disable it. (as well as anything else you don't need running everytime the computer is turned on). Do the same thing in the Services tab after checking hide all Microsoft services.
Strange that a graphics card would have that effect. You haven't installed a wireless mouse/keyboard or laser mouse? All of these things can cause your monitor not to power off as it should. Anything that is sending a user-induced signal actually.
Also - Do you have multiple monitors? Or have you installed any screensavers?
Well, try the above and post back. Good luck!