Solution : https://service.sap.com/sap/support/notes/718779 (SAP Service marketplace login required)
Key words : 
calculation rule 'percentage', latest ipc patch, sap service marketplace, standard copying routines, copying routine 4, copying routine 5, condition control, terms crmstandardexits, ksteu reason, 0 support package 12
Related Notes : 
       
| 530835 | IPC Support Packages for CRM 3.0, CRM 3.1 and CRM 4.0 | 
| 486061 | How to get patches for CRM Internet Pricing Configurator |