Hmmmm... question: did you get some high temps into GPUz? Was it possible to see the temp issue? Or did you discover it only when removing the waterblock?

I'm asking this question because now I have a doubt... and I'm not sure that driver issue was the only provoking component... of lockups. I didn't noticed any temp issues, on logs in GPU-Z. But do you think I'll have to check? Because I swap my card with some nVidia and if there is any risk I want to warn the new owner of my card and ask him to check if contact is good or not... if required.