Solution : https://service.sap.com/sap/support/notes/595590 (SAP Service marketplace login required)
Key words : 
system posts incorrect data, -pa characteristic 'customer group', cross-company-code sales, incoming sales orders reason, delivering company code, external customer displayed, intercompany cross company, attached program correction, incoming orders, sales document
Related Notes : 
       
| 629705 | Incoming sales order: cross-company code orders | 
| 595514 | Incorrect charactrstcs for internal incoming sales ordrs III | 
| 565621 | Incorrct chars. with intercompany incoming sales order II | 
| 498072 | CO-PA: Incorrect characteristic values for intercompany | 
| 396685 | Customer group for cross-company code sales | 
| 395054 | Incorrect chars. for intercompany incoming sales orders | 
| 355001 | Incorr data f profitability segment characteristics |