Power Saving Mode

Hope someone can explain:

Installed a Radeon X1950 series graphic card. I have been able to play multiple games, use microsoft programs, etc. with no problems.
Installed a new game; can play for about 5 minutes, then the graphics start breaking down, the "Power Saving Mode" on the monitor starts flashing randomly over the screen, then the computer will blue screen and do a dump, causing the computer to shut down and have to reboot all on its own within 2 minutes of the graphics messing up.

I have had no problems with any other application, and can go back and run other applications with no problems. Just when I attempt to play the new game (which is also an online game), does the problem occur.

Operating system is 32-bit Vista. The driver was updated when card was installed, verified again to make certain it is current.

The only assumption that I can figure is the monitor itself does not believe there is any activity, therefore it is turning on its "Power Saving Mode." The display settings have the power saving mode turned off through windows. I have also tried to check the monitors settings, finding no way to turn off the "Power Saving Mode" message.

The monitor is a lenovo 22" wide screen.

Any suggestions?