Windows Evolve graphic glitch on retina iMac

Hi, I'm getting a graphical glitch while playing Evolve on my retina iMac. Symptoms are a roughly rectangular patch of flickering black squares in the upper-right part of the screen.

This only usually happens near the start of a game, lasts for maybe a minute and goes away. It may come back later on but usually does not.

iMac specs:

• Retina iMac 27"
• 16GB RAM
• AMD Radeon R9 M295X
• Windows 7 Bootcamp

Evolve graphics settings:

• Full Screen
• Resolution: 1920 x 1080
• Anti-Aliasing: SMAA 1TX
• VSYNC: 1 Frame
• All Other Advanced Settings: Very High

I've tried lowering the resolution, removing FSAA and VSYNC, but it still seems to occur.

Is anyone else observing this behaviour? I can live with it, but I feel that I shouldn't have to.

I considered changing from default Bootcamp AMD drivers to the official ones but a google search shows me that this is actually not as easy as it sounds and may cause problems with my system. But please let me know if you've had success with this.

Thanks for any info.

So yeah, just bumping this.

I am wondering if the lack of replies indicates that I am the only one with this problem? Can anyone confirm they have Evolve running on highest settings on retina iMac, glitch-free?

For what it's worth, the latest Apple graphics driver for retina iMac fixed this behaviour!
So I guess it was a driver issue after all.