SLI flickering with some videogames

Hello,

I am sure this problem occurs a lot but I tried searching and have not found any solutions to the issue.

My computer has the following:

- 2-way SLI EVGA GTX 560 SC
- Gigabyte GA-890GPA-UD3H momo (This mobo is not SLI compatible out of the box so I applied the SLI patch)
- 8GB Corsair Vengence LP + 4GB Corsair XMS3
- AMD Phenom II X4 965
- Corsair HX1050 Silver 80 Plus PSU

My mobo and GPU did not come with an SLI cable so I bought an MSI cable off Ebay. And some games run VERY well, here is a list of games that run perfectly fine and have increased performance as expected:

- Witcher II, Crysis 2, Skyrim, Arkham City.

However, there are some games that have a terrible flickering to the point it's unplayable.
- Crysis, Crysis: Warhead, NFS Shift 2 Unleashed, Dragon Age II (possibly more games that I haven't tested yet.

Upon searching, I found that there are a few possible causes for this including:
- Bad SLI cable, insufficient PSU power, improper GPU drivers, game not patched to latest version.

It certianly isn't a hardware issue for me as I have the latest video drivers from N-vidia, my PSU is MORE than sufficient, and I apply the latest patches to my games, some are not completely updated such as Crysis 2, but it still runs perfectly fine. and the fact that several videogames run fine with this setup shows the hardware is all well and fine.

It's not a bad SLI cable as there is usually a colored flickering involved with that.

But the videogames that flicker will only do so in Full Screen mode, if I play the game in windowed mode, the flickering stops. But I would much rather play in full screen mode.

Does anybody have any suggestions?