I've installed compiz setting manager. I interested in winodw management section, grid plugin.
The short key for "put center" is KP5, i assumed that is Ctrl+Alt+5. But when I using this combination nothing changed. The num is on on the numpad. What exectly should I press to move window to the grid? Thanks.

UPDATE: Maybe the problem caused by virtual machine? I'm running Ubuntu as guest machine. But another hotkeys work well.