You are right, the drivers are pretty old. Problem is: It's not possible to update them. My computer (a Notebook made by Sony) has an hardware switch, which allows me to switch between the AMD graphic card and the graphic card which comes integrated in the Intel CPU. Thus it needs a special driver package made by Sony to make this hardware switch work. Installing a driver taken directly from AMD will break it's functionality. And as you can probably guess: Sony didn't release any new Version of the driver. So, thanks to Sony I'm stuck with this outdated Version.
I also made a new discovery today, regarding said switch: Switching to the Intel graphics does resolve the issue with the glitches.
However it's no real solution, since the Intel graphics is just painfully slow.
