I'm confused....
In one post you say that the batteries are not connected to the Arduino, but then you agree with my post and say yes you have connected power to the Arduino as in that link.
But assuming you do have the batteries connected to Arduino you might be short on volts. The link says use 5x alkalines which will give you 7.5v @ 1.5v each.... you say you have 5 x 1.2 which is only 6v and below the recommended 7v for the barrel jack input.