It was working mostly by chance, as given the limited dofs of
turtlebot_arm, we must calculate the heading from arm base to the place
location (first we must transform its pose to arm base frame) as
pick/place yaw.
Morover, to make place work, we subtract the yaw we calculated for pick,
as the picked object "carries" with him the orientation of the arm at
pickup time. More details in this moveit-users group thread:
https://groups.google.com/forum/#!topic/moveit-users/-Eie-wLDbu0