I've installed a CompizConfig Settings Manager on Ubuntu 10.10. A filter in the program disables "hide all normal windows and set focus to the desktop" because of a conflict. I don't know what is causing the conflict - I tried changing its shortcut key but that didn't help. I also tried uninstalling CompizConfig Settings Manager, but still it didn't help. I was thinking that there might be a configuration that have disabled it but I don't know where to look for it. How can I re-enable the shortcut to hide all windows and set focus to the desktop?