When I press my Sentry Turret bind ("Q" or MOUSE4 button currently) with my Demon Hunter, and the mouse cursor is near the upper edge of the screen, my character starts to move towards the cursor instead of placing the turret. The turret won't be placed when the character stops moving. The bug happens both on/off cooldown and with all runes. Didn't notice this behavior with other skills. When the character's path is blocked it will place the turret properly, even if the cursor is too far. Experimenting with the bug led me to believe that it's related to the distance between the cursor and the character in the game world. It does not happen when zoomed in.
Edited by Ceriulun#2442 on 12/4/2012 7:10 AM PST