public function save(Application_Model_Profile $profile, $exists)
 {
     $data = array('user_id' => $profile->getUserId(), 'first_name' => $profile->getFirstName(), 'last_name' => $profile->getLastName(), 'birthdate' => $profile->getBirthdate(), 'gender' => $profile->getGender());
     if ($exists) {
         unset($data['user_id']);
         $this->getDbTable()->update($data, array('user_id = ?' => $profile->getUserId()));
     } else {
         return $this->getDbTable()->insert($data);
     }
 }