This is an odd thing that might or might not be a bug. I was adding a vignette to an image and noticed an odd change to parts of the image. This oddity is best described as random increases to highlights. What I discovered is this happens only when there is a degree of clarity and structure add to the image. It didn't appear when only clarity was added. You only see it while using the slider. It disappears once you let go of the slider.
Actually, it is a good way to see exactly where the structure is being added. Something I never really wanted to know, but, it is a minor bug with a potential use. Of course, I hope it is in the program and not another issue with my copy.
This seems to have been fixed in the 9.01 upgrade.