voucher that are posted, paid reflect address change when vendor adddres changes

Hello,

Has anyone experienced this issue or should I say is a Oracle bug? I have this scenario:

Voucher A and Voucher B were created in Jul 2015 using Vendor 123 Loc 1 which has following remit address

100 Main Street

Any City, USA

Voucher A and Voucher B were posted for accruals.

Only Voucher A was paid in July 2015 and and payments.

Voucher B is scheduled for pay in Nov 2015.

AP gets a request from Vendor on Oct 1 to change their remittance address from Oct 1 2015 to the following:

PO Box 1111

Any City, USA

Once the change is made, the assumption is that anything that were