I've used Ubuntu 14.04 LTS for 3 weeks. My laptop's(Samsung RV510) function keys did work for volume changing until now. Yesterday they suddenly didn't work anymore when I turned on my computer.
I still can use my Fn keys to change brightness of monitor for example.
If I open System settings -> Keyboard -> Shortcuts -> Sound and Media:
Then Volume down is set to "AudioLowerVolume" and Volume up to "AudioRaiseVolume". These values are same, if I press my Fn key + buttons I want to control the volume, but still can't change the volume with them.
But if I bind F9 and F10 for example, then it works, then I can use these button to control the volume. If I bind Fn+F9 and Fn+F10 then it doesn't work. It means, something is up with my Fn keys.
Tried to google, didn't find answer to my problem. Hope you can help me!