I wish I'd known that years ago. I always use solid colors for background as it's less of a distraction (I suppose if I'd alternated between an image and solid color I'd have noticed it but I didn't).

The question remains why didn't Microsoft notice the problem at the time as to the programmer it should have been obvious. But then from experience I think I've answered that already.

BTW, I've still some old machines with Win 7 so I might experiment with it.