Parallax ColorPal Sensor and Arduino Mega ADK board

Hi, I am trying to set up the Parallax ColorPal sensor in a Mega ADK board. I do the wiring as indicated and loaded the code uploaded by Parallax (below). Although the sensor's LED flashes upon initiating the serial monitor there are no readings coming into it. There is a post by mrjetplane from past january with a similar comment and question?. I would appreciate help in making this sensor work. Thanks, Alejandro.