Solution : https://service.sap.com/sap/support/notes/842887 (SAP Service marketplace login required)
Key words : 
execute transaction i18n -> folder 'troubleshooting' -> double-click 'ccc cache' -> button 'clear cache', note administration -> tabstrip 'sp patch level', code page converter cache, tabstrip 'regional options' section 'standards, arabic-indic digit shapes, required kernel patch level, select button 'customize', 20 requires sap kernel release 6, enable printing ascii digits, control panel -> regional
Related Notes : 
       
| 1375438 | Globalization Collection Note | 
| 809034 | Support for Arabic with SAPWIN | 
| 689015 | SAPscript/Smart Forms: Print preview for Arabic | 
| 587150 | Support of Arabic-script languages |