Take a look at this:
Code:
<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPages/Frontend.Master" AutoEventWireup="true" CodeBehind="Template.aspx.cs" Inherits="$relurlnamespace$_$safeitemname$" %>
Look at the CodeBehind reference: it still says Template, rather than this:
CodeFile="$safeitemname$.aspx.cs"
Also, it should be CodeFile rather than CodeBehind. Here's the first line of the template that comes with the book:
<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPages/Frontend.master" AutoEventWireup="true" CodeFile="$safeitemname$.aspx.cs" Inherits="$relurlnamespace$_$safeitemname$" %>
I recommend you either redo the template exercise, or copy the one from the book to your ItemTemplates folder on disk.