The following workaround worked; just as advertised above (Thanks!) :
I ran these in konsole:
1. cd /usr/share/icons/oxygen/16x16/actions/ 2. sudo ln -s document-properties.png gtk-properties.png 3. sudo gtk-update-icon-cache /usr/share/icons/oxygen/
Now inkscape behaves as it should.
The following workaround worked; just as advertised above (Thanks!) :
I ran these in konsole:
1. cd /usr/share/ icons/oxygen/ 16x16/actions/ properties. png gtk-properties.png icon-cache /usr/share/ icons/oxygen/
2. sudo ln -s document-
3. sudo gtk-update-
Now inkscape behaves as it should.