It seems like the cookbook does not recognize that you are logged in. Maybe somethings wrong with the installation? Have you installed the servicepack?
I've seen this topic and i have the same problem with comments. I'm logged, but i've no button to submit my comments. I've tested it in admin and in registered user, it do the same thing.
Does anyone has solve this problem ?
Thank you for your answer
Have a nice day,
6mille