Solution : https://service.sap.com/sap/support/notes/834501 (SAP Service marketplace login required)
Key words : 
rdisp/plugin_auto_logout overrides icf timeout, security info file triggers errors, client/server technology area, disp+work reason, sap web dispatcher, work process waits, update work processes, snc-secured connection, multi-threaded programs, registered rfc server
Related Notes : 
       
| 835474 | More than 32 GB extended memory | 
| 834084 | R2E Session is waiting for APPC input: ONE option | 
| 834077 | rdisp/plugin_auto_logout overrides ICF timeout | 
| 833770 | GW: Gateway program terminates when you exit | 
| 832220 | Retaining Unicode characters in HTML documents | 
| 831514 | Problems after offline backup | 
| 829012 | LG library in multithread programs | 
| 827872 | Work process waits for registered RFC server | 
| 817854 | RFC using SNC secure connection | 
| 812696 | Update work processes in the UPD status | 
| 804020 | "duplicate conversation" message in librfc |