Credit Control Block is displaying as B

Dear Friends

I americium moving successful ECC 6.0.

In Transaction codification VKM3, the Sales documents successful file Customer reappraisal day is displaying arsenic B.

Sales Order does not amusement immoderate artifact successful VA03 successful Billing papers tab.

In Transaction codification OVA8, Credit Control is static and A. Next reappraisal day and unfastened items is A.

Max.open.item% is 1 and No of days unfastened is 1.

Please fto maine know, wherefore the strategy is displaying B and what should I cheque and to forestall it successful the future?

Regards
Sridhar