Roedy Green said:
The bloody thing disappeared for about an hour, then just as
mysteriously reappeared.
This must be part of the "desktop metaphor". It is a very common
phenomenon and often happens with spectacles and car keys. I firmly
believe that these objects move into the future and can only be seen
when your time catches up with them and they appear on your desktop
exactly where you know you looked twenty minutes ago. While many
people scoff at the theory it does save a lot of fruitless searching.
My equivalent for the virtual desktop is to turn the computer off and
on again but I guess you tried that.