When I close the screen of my netbook in Kubuntu, it doesn't lock when I reopen, and when I press the lock button, nothing happens. I have KScreenSaver configured, and all the drivers work fine, so how do I get my computer to lock?
i had to install the
laptop-mode-tools package to get mine to lock.
i've now been able to set up my laptop to hibernate on lid close without any trouble.
use muon-package manager or
sudo apt-get install laptop-mode-tools to install
EDIT: i've noticed an issue hibernating after my update to precise and thought it was just a hick-up caused by one my customization. but it's a "feature" added to 12.04.
From 12.04, hibernation is disabled by default for all Ubuntu OSes, you need to create a file and add some configuration data to it as per this official page.