any cure for deleted key bindings?

[Vojtěch Polášek]

Hi,
I am still experiencing deleted keybindings for working with windows and
desktops in Ubuntu 12.04. Is there any definite cure for this?
I lose always the same keybindings:
- switching among windows
- switching among system elements
- hide all windows
- moving among virtual desktops
and probably all key bindings in window section.
Thank you,
Vojta