Account xxxxx requires an assignment to a CO object at the time MB1A transaction

Dear SAP GURU’s,

please help me in the below mentioned issue.

A business requirement is to scrap obsolete material and the profit center assigned to the material master must be posted at the scrap transaction.  There is a profit center assigned to the material.  The inventory scrap will post to a scrap GL expense account with a cost object (currently is IO).  The cost object has assigned to another profit center.  The requirement is the profit center on the scrap transaction should be the profit center defined in the material master.  I have done a test.  The scrap transaction initial will pick up the profit center defined in material master and then it is replaced by the profit center defined in the cost object at OKB9 process time. I don’t want profit center overwritten OKB9 settings at process time.