Sorry for not responding for so long. I have a good news - it seems I've found the solution.
And... yes, it was the map. I still don't know what cause the same error in Guild Wars 2 (I haven't played it for some time though).
Thank you for all tips and advices. I've done memory tests of my video card (or rather - both of my memories, because the X2 model has two GPUs and memory divided into two parts) and here are the results:
My first GPU temperature is pretty high, but I remember it was always like this - around 80 degrees Celsius in idle mode. The second one is around 60. They don't change much when playing games (not more than +9 degrees each).
Long story short - the computer is perfectly fine (and thanks to you I'm now sure about it, so thank you
). Problem is probably a mix of Esenthel/Guild Wars 2 technology and AMD's drivers. And something we did wrong along the way probably.
What caused the driver to crash exactly? A volumetric cone light based on a template of a point light. I'm not sure, maybe it was something corrupted in the map data, maybe something in light parameters. But after deleting it I created a lot of correctly defined lights around the map and worked for some time without problems. I attach below a package with the area with that light (-2,-3) and a screenshot to help you find it (I added only templates of the lights, without other objects). I hope you will find this useful somehow.
corrupted_light.zip (Size: 243.58 KB / Downloads: 1)