Why does my monitor flicker until I change resolution?

I have one Sapphire Radeon HD 6950 2 GB DDR5 Graphics card in my computer.

Everything used to work great. One day my friend and I flipped the switch on it to enable overclocking and I overclocked for a little while. Everything was great. I only overclocked a little bit, nothing too crazy. The default is 800 Mhz, I think I bumped it to 850 Mhz tops.

A couple weeks later I purchased a 1080p monitor to go along side my 1650x1050. Everything was still going great.

A couple weeks after the monitor purchase, I notice that both of my monitors are flickering like crazy. Whenever I move the mouse, or scroll on a browser window for example. Horizontal lines are flickering all over the place. Almost looks like some of the image is displaced in a different location, but happens very fast.

I've realized that if I go into my resolution settings and change the resolution on the 1080p monitor from 1920 x 1080 down to 1650 x 1050 and then SET IT BACK UP to 1920 x 180, everything works great until I reboot the computer. I forget there is even a problem until that point.

I have now disabled the overclocking, and the flickering still occurs on startup.

Does anyone know what could be causing this? And why it is being "fixed" when I reset the resolution manually?

Update I just updated my motherboard BIOS, still flickers.

Change your Power Plan settings

The power plan is limiting the resources for the graphics card to function properly. Change all the settings to the Maximum Performance.

How I fixed the problem:

• Install the latest drivers from the official AMD website (Catalyst 14.0+).

• Change you Power Plan to High Performance (in battery and plugged-in).

• Go to Control Panel>Power Options>Change advanced power settings> ATI Graphics Power Settings> ATI Powerplay settings> On battery, Plugged in: Maximum Performance.

• Go to Control Panel>Power Options>Change advanced power settings> PCI Express> Link State Power Management> On battery, Plugged in: Off.

• Disable Aero (Choose the Windows 7 Basic theme)

• Restart your PC.

Important: This will also fix a constant change in the brightness level when you switch between dark and bright apps.