Solution : https://service.sap.com/sap/support/notes/949642 (SAP Service marketplace login required)
Key words : 
solution source code correction, condition based tax calculation, classic tax calculation, multiple-account assignment, transaction miro, view j_1bkon1v, transaction sm30, multi-accounting, numbering exists, item 1 referring
Related Notes : 
       
| 1012077 | Multiple account assignment - nota fiscal items lost | 
| 883582 | MIRO: balance error (PO with multiple-account assignment) |