Solution : https://service.sap.com/sap/support/notes/111781 (SAP Service marketplace login required)
Key words : 
additional key words 20c_hp5   20d_hp2   jva, debit/credit indicator, fi integration manager, exchange rate difference, exchange rate, document lines, local currency, jv document, set wrongly, wrong split
Related Notes : 
       
| 517975 | JVA IM: Set DR/CR indicator w/o changing signs of amounts | 
| 129320 | IS-OIL: Applying LCPs 29 to 32 on R/3 3.1H | 
| 129319 | IS-OIL: Applying SPs 29 to 32 on R/3 3.1H |