This problem is driving me nuts: I cannot logout neither from lxde
using lxde-logout nor from jwm using jwm -exit. And even C-A-Backsp
does not work.

I'm logged out yes, but then i end up in dead terminal with the
underline cursor up left.

This is true as any user, also as root.

The /var/log/slim.log does not tell anything interesting. I installed
lightdm, to see if it's in some way eventually a slim problem but it
isn't.

But the logfile, eventually, tells something (but i'm not really able
to understand). This are the last lines:

--------
[+27.22s] DEBUG: Session pid=2982: User <> authorized
[+27.22s] DEBUG: Session pid=2982: Greeter sets language de_DE.utf8
[+27.27s] DEBUG: Session pid=2982: Greeter requests session jwm
[+27.27s] DEBUG: Seat: Stopping greeter; display server will be re-used
for user session
[+27.27s] DEBUG: Session pid=2982: Sending SIGTERM
[+27.30s] DEBUG: Session pid=2982: Greeter closed communication channel
[+27.30s] DEBUG: Session pid=2982: Exited with return value 0
[+27.30s] DEBUG: Seat: Session stopped
[+27.30s] DEBUG: Seat: Greeter stopped, running session
[+27.30s] DEBUG: Registering session with bus
path /org/freedesktop/DisplayManager/Session0
[+27.30s] DEBUG: Session pid=4517: Running
command /etc/X11/Xsession /usr/bin/jwm
[+27.30s] DEBUG: Creating shared data
directory /var/lib/lightdm/data/<>
[+27.30s] DEBUG: Session pid=4517: Logging to .xsession-errors
[+27.44s] DEBUG: Activating VT 7
[+27.44s] DEBUG: Activating ConsoleKit session
e3ac7b4a2da4fecc7b2c5bed5740af60-1464012627.597710-1157014337
[+27.44s] WARNING: Error activating ConsoleKit session:
GDBus.Error:org.freedesktop.DBus.GLib.UnmappedError.CkVtMonitorError.Code0:
Session is already active
--------
I'm absolutely clueless - especially since it worked for a moment. But
i didn't do anything and after a restart it was all over ... :-(