Color picker "pick from screen" doesn't preview screen pixels with the right screen coordinates

As you can see in my screenshot here:



The color picker is definitely doing something funky. Although my mouse is over the green baguette, the preview is showing my RubbleMasonry normal map. The preview image is flipped too--those letters that look like 'p' are actually upside-down 'b's.

However, when I click to pick a color it seems to pick it correctly. So that's good!