Solution : https://service.sap.com/sap/support/notes/687304 (SAP Service marketplace login required)
Key words : 
tax code reason, tax calculation, tax categories, assigned formula 331, condition type, sales organization, condition record, terms argentina, program error, localization
Related Notes : 
       
| 706542 | Argentina : Incorrect tax data in Credit Memo | 
| 506672 | Argentina VAT and GI Perceptions in Release 4.7 | 
| 155001 | AR:SD: Errors on pricing involving gross income perception | 
| 102852 | AR:SD: VAT perception and customer exemption |