When i walked throuh a front door and logged out, i was trapped under the house floor on earth level after logging in again.
It was a house like this: http://mmo.justnetwork.eu/files/2013/02/DayZ_Haus1.png
i was unable to leave this trap until i lagged and jumped trogh the stair from "below".
I searched for restart or "suicide" button but you only can restart when uncotious so it was a really awkward situation :).