Ubuntu, VirtualBox captures system keyboard shortcuts. How to wean him?

Question

virtual box

On Ubuntu 14.04, one of the desktops is running VirtualBox. Switch between desktops Ctrl+Alt+UP/DOWN. Desktops switch normally. But in the active window of the virtualized system, these hot keys do not work until you press the Host key. It is very uncomfortable.
How can I tell VirtualBox not to capture this keyboard shortcut?

Answer 1

Also faced this problem.
It is solved very simply. Open virtualbox:
File -> Settings -> input -> keyboard autocapture (uncheck) - Enjoy!