Solution : https://service.sap.com/sap/support/notes/935968 (SAP Service marketplace login required)
Key words : 
sql agent jobs created, -schedule faulty backup jobs, sap netweaver 2004s technology, sap netweaver 2004s sr1, sap netweaver 2004s documentation, overwrite existing backup sets, sap_basis support package level, append sql server database, sap db13 job tables, sap netweaver 2004s
Related Notes : 
       
| 1054689 | DB13-Sick MSG:Jobs are created with wrong backup parameters | 
| 1011864 | DBACOCKPIT - DBCON Connection is not working | 
| 937906 | Backup jobs(WITH NOINIT) shows 'Red' status(SQL2005) | 
| 919107 | SAP NetWeaver 7.0 SR1 Installation on Windows: SQL Server | 
| 905029 | Add. info.: Upgrade to SAP NW 2004s Support Rel. 1 ABAP | 
| 849142 | SAP NetWeaver 2004s Installation on Windows: MS SQL Server | 
| 826488 | Enhancements to upgrade on SAP CRM 5.0 ABAP | 
| 826093 | Add. info. on upgrading to SAP SCM 5.0 ABAP | 
| 826092 | Add. info. on upgrading to SAP ERP Central Component 6.0 | 
| 818322 | Add. info.: Upgrade to SAP NW 2004s ABAP |