Nautilus allows the user to drag colors into the window to change the background color to a solid color. If the user drags a color to the edge, Nautilus will gradate colors across the view. Unfortunately, the hotspot around the edge is small and sometimes hard to hit, making it easy to accidentally set a solid background instead of a gradient.
not detrimental - will pass information upstream for future fix
created upstream bug in nautilus bugtracker - shown in URL field