In testing HoD in beta 18, I found this:
When entering a room that has a string message and quickly leaving it (back to the original room) you get stuck, resulting in having to Quit -> continue.
I don't know if it matters, but it is a cave dmap, and entering the screen (with a string and guy) from the west side. And I travel through the rooms through a door that is half a tile. And it works otherwise. You only get stuck when you rush out of the room before the string starts.