Solution : https://service.sap.com/sap/support/notes/510431 (SAP Service marketplace login required)
Key words : 
project planning board, terms gantt chart, sap gui error, sap gui newer, 'highlight project elements', function 'position, correctly position, graphic vertically, graphic starts, positioning reason
Related Notes : 
       
| 500933 | Proj.plng board: Recomm., additional information, consulting | 
| 30460 | SAP GUI: Compatibility with different SAP Systems |