I'm using BAPI_PO_CHANGE to turn off the PO item GR indicator flag. After each PO change, I call the BAPI_TRANSACTION_COMMIT function module. This process works very well in our development system, but does not work properly in our staging system. My test includes 4 different purchase orders with one or more items being changed. In the staging system, only the first PO change gets written to the data base. The return table contains the successful PO Changed message for each PO. The BAPI is the same in both systems.