Asus HD 6870, flickering issue

[longify]

First of all hello from a new user, I have a problem with my computer but I need help to nail it down to one part (I think it's the graphics card, but who am I to tell).
A friend of mine said people over here are very nice and competent so why not try to get help here.

Long story short, I played a game, Velvet Assassin, that is rather buggy (I.e. it didn't let me change the resolution to my native 1680x1050).
After some time the screen started flickering in complete white with some color bars here and there. I thought it was another bug on newer systems and changed the resolution; the problem seemed resolved.

Until my little brother started to play Forge of Empires, that little browser game, where the problem again occured at an even faster rate.

I hope you can help me, I made a short video of the issue, I know it's not of best quality, but maybe it helps.
Thank you in advance

 

[Cobalt006]

Have you tried updating your drivers? Also could you please post the make and model of your laptop /desktop and the system specs.

 

[longify]

Of course, sorry.
Specs: MB:
ASRock 970 Extreme 3 AM3+
CPU: Phenom II X4 965 BE
GPU: Asus Radeon HD 6870
RAM: 8GB Corsair Vengeance LP DDR3-1600 (2 * 4GB)

Updated the drivers already. Unfortunately nothing changed.
I also checked the RAM for errors. I'll try another monitor if I get my hands on one or I'll try to record my screen. If it's display related the error won't be recorded, am I correct?

 

[Cobalt006]

Yes do try another monitor. On the video you have now. It looks like a refresh rate problem.

 

[longify]

So yeah used Fraps to try to record the phenomenon and turns out it's not on video. So it indeed is the monitor. (Supposedly?) What I don't understand though is why it does occur every 5 seconds when playing Forge of Empires but not while surfing the web normally.
I also tried the ufotests online since you mentioned refresh rate and I thought I could see it there, too. Well nothing happens at all unfortunately...

Do you have a guess as to what's up with Forge that it would make the monitor go all bonkers?
I mean it happens with Bioshock 2 too, but only like every 20 minutes..

 

[Cobalt006]

This I can not answer. I do not do a lot of gaming. I can just tell its a refresh rate problem. Dose it do it on another monitor?