Mission Control has no spaces, background image doesn't change and Launchpad background is dark I just ran a system update on Lion and after the reboot I got issues with Mission Control.

Namely,


When I trigger Mission Control, it only shows windows on current space and doesn't provide a way to add or switch between spaces. The whole top bar is missing.
When I trigger Launchpad, it shows on a background that has nothing to do with the desktop background image, as if the underlying image was black.
Changing background image in Preferences doesn't take effect until a restart.


This is very frustrating and seems like a bug. How do I fix this?
Seems like I'm not the first one to hit into this issue, and it is related to Dock process working incorrectly. The easiest way to fix this is to type 

killall Dock


into the Terminal, which will effectively relaunch Dock process (and hopefully fix the problem).

If this doesn't work, reportedly trashing Dock preferences and attempting several restarts may help.