Encountered a weird problem, on Ubuntu 14.04 LTS, suddenly I was not able to launch home folder with nautilus using Super + E , nor to launch terminal using Ctrl + Alt + T.
More syndrome includes that I could change the shortcut settings in Settings > Keyboard > Shortcut to make the functions work, but I did not want to change my habits.
The solution is rather simple. The following commands needs to be run in terminal.
dconf reset -f /org/compiz/ setsid unity
Voilà! The good ol’ shortcuts are working again!