The only way I found to solve this problem is to install ccsm
$ apt-get install compizconfig-settings-manager
Open ccsm
$ ccms
General -> Commands (or Shortcuts (i don't know its name in your localization)) And set your shortcuts here.
The only way I found to solve this problem is to install ccsm
$ apt-get install compizconfig- settings- manager
Open ccsm
$ ccms
General -> Commands (or Shortcuts (i don't know its name in your localization))
And set your shortcuts here.