SOLUTION:
Some others may experience this issue down the road.
Imar has discovered that the issue I was experiencing was being caused by a line of code in the Page_Load event of the file MasterPage.master code behind (either MasterPage.master.cs or MasterPage.master.
vb). That line of code is
this.ID = "Master"; (in C#)
There are two simple solutions to this problem:
1. You can create an alternative event handler and place the same code into THAT event like this
protected void Page_Init(object sender, EventArgs e)
{
this.ID = "Master";
}
Of course you would then remove that line from the Page_Load event handler.
2. You can remove the line
this.ID = "Master";
altogether as it is not required for the project to work correctly.
This line of code was
suggested and is not a part of a 'try it out' in the book. The explanation for the use of the line can be found on page 276 in the book (Chapter 8) under a caveat.
I hope this helps anyone who comes across this in the future!
Gerard Torres