To which edition of the book does this apply? You're better off posting in a category specific to the book which you can find here: http://p2p.wrox.com/asp-net-asp-12/
That said: it looks like your custom template is messed up a bit. Does this happen on new pages? Or just whenever you try to run a page? In the former case, you should follow the steps again to create the template, as it looks like you made a typo somewhere. In the latter case, you may have forgotten to delete the Temporary page you created for the template.
Hope this helps,