current symfony2/doctrine is picky about the case:
$ php app/console doctrine:generate:entities 'Blogger\BlogBundle'
Generating entities for namespace "Blogger\BlogBundle"
[Doctrine\Common\Annotations\AnnotationException]
[Semantical Error] The annotation "@Doctrine\ORM\Mapping\preUpdate" in method Blogger\BlogBundle\Entity\Comment::setUpdatedValue() does not exist, or could not be auto-loaded.
current symfony2/doctrine is picky about the case: