I have the same problem in feisty, in a sony vaio laptop: VGN-FE31H. The keys used to work OK, but some update about 2 weeks ago broke their functionality.
When I press any of the OSD info appears, but the bar is empty, and does not increase. I can change the volume in sound volume applet. Mute key works fine. Sound card is an "Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 02)" -- Keyboard volume hotkeys stopped working https://launchpad.net/bugs/28834 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
