I've already reported this on upstream a little less than a week ago, before I knew about Launchpad. Please don't chew me out too bad.
http://bugzilla.gnome.org/show_bug.cgi?id=336783 -- Volume keyboard shortcut fails to increase volume https://launchpad.net/malone/bugs/36302 -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
