Rob Allen has made some updates to his Zend Framework tutorials - one becuse of a bug in the code (ID!=id) and others by way of updates:

I've finally updated the source code to my Zend Framework tutorial so that the hidden field in the form is named "id" rather than "ID". A minor error that meant that editing didn't work! This is because in PHP $_POST['id'] is not the same as $_POST['ID']!

His other update was on the Zend_Auth tutorial to change the database variable to make it more consistent. Updated zip files for both are now available.