I am using a computer that started out on 11.10. I have since updated it several times, and installed and used a great number of WMs (Unity, XFCE, Gnome, KDE, Cinnamon). I am not sure how, but somewhere along the way (probably when I upgraded to Ubuntu 13.04), some parts of my desktop theme were broken. I have tried switching themes and installing new themes, but that does not work. Neither did a removal of (and log out/login cycle) the ~/.config/dconf folder work.
- on several menus, the central part of a button icon is a "grey square" that doesn't fit in with the theme (picture below).
- the window and desktop right click menus looks ugly. The same kind of grey field covers the items, and the square checkbox looks weird (just filled with a uniform blue). The separator is a thick line that looks out of place. It seems to be a similar problem to that of window buttons (picture below).