Solution : https://service.sap.com/sap/support/notes/435573 (SAP Service marketplace login required)
Key words : 
system translates, delivery incorrectly, document currencies, oli8 reason, fields correctly, document currency, delivery event, reorganization, prerequisites, translation
Related Notes : 
       
| 443609 | SIS: Incorrect conversion of/with AP fields (2) | 
| 434996 | SIS: Incorrect conversion of/with AP fields (1) | 
| 204130 | SIS update: Collective note | 
| 203266 | SIS setup:Val.fields in deliv., MCLIPS-AP* fields | 
| 174141 | SIS: Collective note - Customizing |