Image artifacts in "Quality" preview at low (25%) zoom?

I'm seeing artifacts (See image) in brightly backlit images at 25%, latest C1 Windows, quality previews,  HW accel enabled.


Zooming in removes them, but I often make the gross adjustments at 25% (Fit) zoom, and wondered if anyone else is seeing anything similar, and whether this would lead to tweaks in the reduction algorithm used for display?