I just have had that bug, with volume up and down keys no longer working after changing some shortcuts through "system parameters → keyboard → shortcuts tab"
Solved by :
gsettings reset org.gnome.settings-daemon.plugins.media-keys volume-down gsettings reset org.gnome.settings-daemon.plugins.media-keys volume-up
on Ubuntu 14.04
I just have had that bug, with volume up and down keys no longer working after changing some shortcuts through "system parameters → keyboard → shortcuts tab"
Solved by :
gsettings reset org.gnome. settings- daemon. plugins. media-keys volume-down settings- daemon. plugins. media-keys volume-up
gsettings reset org.gnome.
on Ubuntu 14.04