player spontaneously repositions

(single player)

player character occasionally "teleports" to a new location. so far, all teleports have been within a 1-chunk radius of the player's starting position, and all have occurred during engagements with hostile mobs. the new position does not appear to be affected by the direction or velocity of player movement. one of these "teleports" occurred while player character was standing still, moving it from the top of a roof to a spot on the ground near the house.