After killing Xorg, because it hang, it restarted normally and I just needed to log in again through Slim, but after that until the next restart I experience several authorization issues:
When trying to mount an USB thumb drive through Thunar, by just clicking on the device in the location list: "Failed to mount "Transcend" Not authorized to perform operation.". Same problem with Nemo.
When doing "xfce4-session-logout --suspend" it just will lock the screen instead of suspending, but "sudo pm-suspend" still works, that's why I guess that this is also an authorization problem
Why does this happen? Could it be that I'm logged in twice, because killing Xorg didn't log me out correctly? How can I make mounting and suspending work again like it would on a restart?