It seems that, removing *accessibility packages*, fixes the situation (or at least it cannot occur so easily now).
I just removed these two packages:
< ii gnome-accessibility-themes 2.22.0-0ubuntu1 accessibility themes for the GNOME 2 desktop
< ii gnome-accessibility-themes-extras 2.22.0-0ubuntu1 accessibility themes for the GNOME 2 desktop
It seems that, removing *accessibility packages*, fixes the situation (or at least it cannot occur so easily now).
I just removed these two packages:
< ii gnome-accessibi lity-themes 2.22.0-0ubuntu1 accessibility themes for the GNOME 2 desktop lity-themes- extras 2.22.0-0ubuntu1 accessibility themes for the GNOME 2 desktop
< ii gnome-accessibi