After searching the internet for clues and getting no response at all from the folks at community.phonegap.com. I happened across the answer to my problem here.
The problem was the reference to the childbrowser.js file. While the filename itself is all lower case. The reference that I copied from the guide looked like:
<script src="ChildBrowser.js"></script>
By changing the reference to the lower case version
<script src="childbrowser.js"></script>
Everything worked perfectly in the phone and the simulator.