I am running Windows 7 Ultimate 64bit with SP1 and all other critical updates.
Shortcuts created to the desktop for
optical, (2 SATA DVD burners),
floppy &
USB drives randomly disappear on a regular basis. Sometimes they stay there for days, then suddenly disappear two or three times in as many days.
All other desktop icons remain constant. The icons in question are at top left as shown in this image.
The fixes shown above in this post apply to standard system icons for Windows, and haven't given a solution.