GNOME Bugzilla – Bug 639435
Special keystrokes, including shortcuts and multimedia keys, cease to function when certain applications and menus are open
Last modified: 2011-01-13 21:09:29 UTC
Originally reported at https://bugs.launchpad.net/ubuntu/+source/gtk+2.0/+bug/623922 Certain keyboard, as well as any multimedia keys a computer may have, cease to function when certain applications and menus are open. This includes the menus in the Gnome panel, the game 'World of Goo', available from the Ubuntu Software Centre.
Not a bug. This is simply the way menus are implemented under X, with grab.
It's not just menus that this is happening with, but applications such as some fullscreen games are being affected by it. In these situations, the user is unable to change the volume of their system using the multimedia keys on their keyboard, and they can't minimize the application to do so manually since the keyboard shortcuts they would use are non-functional.