When I try to capture a image of my desktop with rectangular area, and I'm working with two scaled screen, the image of my right monitor mix with my laptop screen (left). When I' working with one screen (whatever) it works right. My laptop screen is 3200x1800 and the external screen is 3840x2160 (scaled is 1.7). I use OpenGl 3.0 and Xorg.
Sorry, OpenGL 3.1
*** This bug has been marked as a duplicate of bug 385885 ***