Solution : https://service.sap.com/sap/support/notes/661580 (SAP Service marketplace login required)
Key words : 
parameter          type      typing method   reference type iv_external_display  importing     type           crmt_mpk_boolean save, enter   methods              level         visibility   set_external_display static method   publicwith, typegv_external_display static attribute protected crmt_mpk_booleanwith description, enter   attributes          level    visibility, directly written intocounter grid, prerequisites program error solution, implement source code corrections, symptom counter corrections related, method 'set_external_display', set display mode
Related Notes : 
       
| 696262 | CRM 4.0 SP Stack 1/2004 (SAPKU40004): Release & Info. Note | 
| 677456 | SAPKU40003: Support Package 03 for CRM 4.0 |