I\'m working on a CodeIgniter project in which I\'m using Doctrine2 and the Symfony2 Validator component.
All my Doctrine2 entities use Doctrine\\ORM\\Mapping
I had a similar issue when using Silex, Doctrine2 and the Symfony-Validator.
The solution was to avoid using the SimpleAnnotationsReader and instead using the normal AnnotationReader (have a look at Doctrine\ORM\Configuration::newDefaultAnnotationDriver). You can then preface every entity with ORM\ (and of course inserting use Doctrine\ORM\Mapping as ORM; in every entity).