Solution : https://service.sap.com/sap/support/notes/70961 (SAP Service marketplace login required)
Key words : 
additional key words idoc, integrated inbox - online -, scheduled report - background, actual database updates, duplicate status values '62', posting incorrect idocs, function module edi_document_close_process_upd, duplicate posting, function module, affected idoc
Related Notes : 
       
| 118924 | Parallel processing of IDocs in the POS inbound | 
| 78935 | Duplicated update of IDocs in ALE Inbox |