I just noticed my primary d960 box (dell [optiplex] 960 (c2q-q9400, 8gb, amd/ati cedar radeon hd 5000/6000/7350/8350)) has no wallpaper anymore on it's top monitor, but 'top' of wallpaper on my bottom monitor.
The box was also used in testing mentioned in comment #3, but windows covered the wallpaper (both monitors) so it took some time for me to notice.
I just noticed my primary d960 box (dell [optiplex] 960 (c2q-q9400, 8gb, amd/ati cedar radeon hd 5000/6000/ 7350/8350) ) has no wallpaper anymore on it's top monitor, but 'top' of wallpaper on my bottom monitor.
The box was also used in testing mentioned in comment #3, but windows covered the wallpaper (both monitors) so it took some time for me to notice.