Solution : https://service.sap.com/sap/support/notes/648673 (SAP Service marketplace login required)
Key words : 
terms sapccmsr agent itsmon plugin, time solution install, uptime wrongly displayed, displayed wrongly, transaction rz20, instances running, remote machines, instance concerned, newer patch, 610 patch 28
Related Notes : 
       
| 584136 | CCMS agents and kernels: Patches 2003 (composite note) | 
| 563161 | SAP GUI, SAP ITS & SAP IGS patches on Service Marketplace | 
| 335521 | ITS patch installation of kernel files | 
| 330793 | Downloading patches |