PDOException : SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'registration Using: commerce+entity registration+commerce registration

During the checkout sequence, after completing the registration step, I get this fatal error: 


  PDOException : SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'registration-144-0-0-und' for key 'PRIMARY': INSERT INTO {field_data_field_nom} (entity_type, entity_id, revision_id, bundle, delta, language, field_nom_value, field_nom_format) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7); Array ( [:db_insert_placeholder_0] => registration [:db_insert_placeholder_1] => 144 [:db_insert_placeholder_2] => 144 [:db_insert_placeholder_3] => formulaire_inscription [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => und [:db_insert_placeholder_6] => dfgh [:db_insert_placeholder_7] => ) in field_sql_storage_field_storage_write() (line 514 in /home//public_html///modules/field/modules/field_sql_storage/field_sql_storage.module).


I have tried to disable some rules that could be problematic, to disable multilanguage (entity registration have some problem whit multilang)... nothing.

What can be the cause of this error?

Thx
If anyone stumble on this error again, note that it is due to corruption in the database. In this case, the registration tables got corrupted at some point.

Just unninstall everything registration related, and start anew.

Thx.