HD 7950 flicker problem in Witcher 2...

I have a HD 7950 and am experiencing some flickering in Witcher 2, even at stock clock. However, I've ran a whole bunch of benchmarks (3dmark11, Unigine heaven, OCCT, furmark) and played several games (Dragon Age Origin, Sleeping Dogs, Batman: Arkham City, Darksiders 2, Metro 2033) without any issues, even when overclocked.

Tried updated to the newest driver, still no avail.

So I've decided to plug in my 5770 and see if the flicker still persist.

Now, do I just install it onto the second PCI slot? How will the system know which graphics card to use?

I don't want having to unplug my 7950 if possible.

Well, its a PCIe slot, first.

Second, you would really want to uninstall the 7950 to test the 5770.

I would imagine it is drivers. Which ones did you try? You said newest...what was the other version?

I am currently using the newest 13.2 beta, before I have 13.1 . Both have the flicker issue.
Is it absolutely necessary to remove the 7950 first?
Couldn't I just plug in the 5770 into the second PCIe slot and make the computer use it as default?

I have never tried. I mean how hard is it to remove it considering you have to add the other one in?