Solution : https://service.sap.com/sap/support/notes/541407 (SAP Service marketplace login required)
Key words : 
terms bp_exchange_crm_to_r3 solution implement, attached source code corrections, contact person relationship, subsequent business partner, avoid sequence problems, existing business partners, resulting mass queue, business partners, mass queue, performance problems
Related Notes : 
       
| 539305 | Performance problems with CSA_MASS queues | 
| 537486 | Composite SAP note:perfrmnce problms during initial download |