Solution : https://service.sap.com/sap/support/notes/1262832 (SAP Service marketplace login required)
Key words : 
mas_employee data object returns duplicate backend keys, symptom user triggers initial/delta download, prerequisites getdetail bapi wrapper, sap netweaver mobile reason, mas_employee data object, terms crm mobile, child node et_org, automatic note, smartphones
Related Notes : 
       
| 1393847 | |
| 1321390 | Release Information Note - Gateway to SAP NW Mobile 1.0 SP01 | 
| 1283581 | |
| 1231994 | SAP CRM 2007 - SP-Stack 04 |