I was on the first floor and going down to the second, in one of the random dungeons, and the "You feel a pulsing surge of power" message was generated into the stairway room I arrived at. There was nothing in the room (and no special rooms on the floor)...This level also had the moving/grinding section of dungeon moving through the room, too. I think this is a bug based on reports that the message indicates a room of monsters with a special monster and artifact generated in the middle. I'm guessing the mechanic of monsters not appearing in stairway rooms has something to do with it? Or, maybe I'm mistaken and it's not an issue.