Super-S doesn't work after reconnecting USB keyboard

Question

Situation: Two laptops using the same USB keyboard and USB mouse (that are both connected to the display which also serves as a USB hub; switching is done by USB cable from the display to the respective laptop). One laptop has Ubuntu 10.04 and works fine, the other Ubuntu 12.04 and this one appears to have the following problem.

When I start it with USB cable from monitor connected everything works OK, but when I either connect USB cable after logging in or disconnect the cable (to use the keyboard for the other laptop) and then reconnect it again, some Unity shortcuts, such as Super + S for showing multiple desktops grid or Super + A for that Unity application menu, do not work.

I have to logout and login back, which of course mean to close everything and is very inconvenient.

Is there any easier way to make it work, restarting some service or something? Thx.

Answer 1

Solved: The same thing may happen even without reconnecting any cable, when after some time unity-2d-shell just dies.

The solution therefore is to issue the command unity-2d-shell, even if it appears to be running. The new one will in such a case exit almost immediately but it will nevertheless “wake it up”.

(Previous comment should have been an answer, sorry.)

Answer 2

Sounds like a bug to me. You could try terminating compiz (the process that handles those functions). To do so type

sudo killall compiz

in a terminal. The process should be restarted automatically.

Note: This only applies when using Unity 3D as a desktop environment. See below for what to do with Unity 2D.