unresponsive screen graphics

[rikona]

Running Ubuntu 16.04 with a number of problems we've discussed on this
list, and unfortunately seem to recur after certain updates. Some
seemed rather mysterious to the list folks so I won't go through those
again. I do run a number of KDE programs, and a few from other
desktops, but no other full desktop is installed.

One hopefully minor problem is that I have several graphics on my
screen that I can't seem to get rid of. They look exactly like icons
that have been on the screen before, but are completely unresponsive
and not listed in the desktop directory. Changing the background
picture on the desktop does not get rid of these graphics - they
appear in the same place in the new background picture. I'd like to
figure out how they are generated and where they are stored and thus
get a handle on how to get rid of them. Any pointers would be much
appreciated. 

Thanks,

 rikona