Confirmed. Thanks Martin! The cause seems quite clear now, LightDM is not detecting the VT switches so when the session exits LightDM thinks it is a background session and doesn't start a greeter (it thinks you are looking at the other session). The reason I haven't seen this is we are using the switch D-Bus calls in LightDM for VT switching in Unity and so LightDM knows which session is active. Using ConsoleKit or logind or doing the VT switches manually will trigger the problem. I think this may be the cause of: <a href="https://bugs.launchpad.net/lightdm/+bug/851612">https://bugs.launchpad.net/lightdm/+bug/851612</a> <div class="gmail_extra"> <div class="gmail_quote">On 24 November 2012 00:40, Martin Briza <<a href="mailto:mbriza@redhat.com" target="_blank">mbriza@redhat.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Well, I reproduced the same behavior in Ubuntu now, too. The only difference is that one can switch TTYs while the screen is stuck. How to do it: 1. Log in user1 2. Switch to greeter, log in user 2 3. ctrl + alt + f7 4. logout 5. bam, vt completely stuck Log: <a href="http://paste.stg.fedoraproject.org/1933/" target="_blank">http://paste.stg.fedoraproject.org/1933/</a> I would try to report it or add it to some bug already opened but search in the bug tracking tool on Launchpad is still redirecting me to the "Lost something?" page, sorry for that. To the difference - there is a problem with login prompt spawning on VTs that aren't managed by LightDM, I'm looking into that now. Can't tell where is this coming from. </blockquote></div> </div>