error while importing users

Hello,

(sorry I'm french and google translate and my friend)

I get an error when any of the members in CSV

Message d'avertissement
SQLSTATE[HY000]: General error: 1364 Field 'signature' doesn't have a default value

SQLSTATE[HY000]: General error: 1364 Field 'signature' doesn't have a default value
Original item

array(
  'mail' => 'asnowboard@hotmail.fr',
  'name' => 'asnowboard',
  'mdp' => 'azerty',
)

Entity

(object) array(
  'uid' => '200',
  'roles' => array(),
  'status' => '1',
  'feeds_item' => (object) array(
      'is_new' => TRUE,
      'entity_id' => 0,
      'entity_type' => 'user',
      'id' => 'import_utilisateur',
      'feed_nid' => 0,
      'imported' => 1367919935,
      'hash' => '104bd21b57fe7579f0b0e74a2134ff63',
      'url' => '',
      'guid' => '',
    ),
  'name' => 'asnowboard',
  'mail' => 'asnowboard@hotmail.fr',
  'pass' => '$S$DrlqdzJUsDc2lUPKMwp7qV1.xRdb7MCeKRt2uhCanHExFptsKRWe',
  'is_new' => TRUE,
  'data' => array(
    'contact' => 1,
  ),
  'created' => 1367919935,
)

How to solve this problem?

thank you