sorry. i posted in english originally because more people here on the forum can benefit from reading reports and your answer.
first of all - ill try occlusion tomorrow and let you know
i didnt just sent a part of the picture. i have used snipping tool to take th at picture. but its showing accurately how its looking on my screen. as offered i can show you via screen share too.
Edit: Its Ambient Occlusion. I had it turned on to 8. When turning down the strange effect got less and by turning it off it was gone completely. What does this Ambient Occlusion do actually?