I'm also experiencing this. Quite frustrating.
I'm on 15.04 and GNOME 3.16 with the gnome3-team and gnome3-staging PPA's.
Only thing to add this message in terminal every time I hit the non functional brightness keys:
(gnome-settings-daemon:13855): media-keys-plugin-WARNING **: No existing D-Bus connection trying to handle power keys
I'm also experiencing this. Quite frustrating.
I'm on 15.04 and GNOME 3.16 with the gnome3-team and gnome3-staging PPA's.
Only thing to add this message in terminal every time I hit the non functional brightness keys:
(gnome- settings- daemon: 13855): media-keys- plugin- WARNING **: No existing D-Bus connection trying to handle power keys