• Désactiver le "Dashboard"
Lancer "Terminal.app" (/Applications/Utilitaires/Terminal)

- entrer la commande :
defaults write com.apple.dashboard mcx-disabled -boolean YES
Et relancer le dock :
killall Dock
*Réactiver Dasboard :
defaults write com.apple.dashboard mcx-disabled -boolean NO
et relancer le Dock
killall Dock