Comment 23 for bug 951000

a similar issue exists with Kubuntu 12.10. lightdm offers a guest session, but
  * Kickoff's Leave menu offers a Lock action that locks the session, and
  * when the screensaver activates, it locks the session.
in both cases, the lock screen's unlock dialog shows an apparently auto-generated username (e.g. "guest-iW6OvM") and requires a password to unlock the session. as a result, the user is stuck in the lock screen.

the unlock dialog offers a "Switch User..." action, which subsequently offers to "Start New Session". but using this to start a "new" guest session actually just switches to the existing session, which is still locked.

a quick workaround is to restart lightdm from the console (ctrl+alt+f1, log in as an admin user, ``sudo service lightdm restart``). however, the previous guest session is lost as a result, along with any work that was unsaved in it. also, it shouldn't be expected that a guest user has access to an admin account.

glancing over the suggestions in the comments here, it looks like the fix may or may not be specific to the session manager, depending on the chosen approach. i see suggestions that appear to be specific to GNOME (via GSettings); my Kubuntu installation has GSettings, but i have no idea whether/how it is used by Kubuntu.

is it appropriate to address this in this bug, or should i create a new one specifically regarding KDE guest sessions?