When Auto-Running (default key "R" keyboard or pressing L1/LB on your gamepad) then casting a spell (ie. Sleep) your character begins the casting while walking toward the target (since face target while casting is ON).
Now this is extremely annoying and a bug. Before, your character would stop in place to cast the skill. Now your character runs toward your enemy doing nothing but walking toward possible death.
Link is a .gif of it in action.
http://i.imgur.com/uz2B4bc.gifv