BDC for VI01 can't transfer

I'm trying to write a BDC from VI01 to create Shipment cost documents. The last step is to go from the main screen to the settlement tab and click transfer and save. That code looks like:

PERFORM bdc_dynpro USING 'SAPLV54K' '0200'. PERFORM bdc_field USING 'BDC_CURSOR' 'VFKN-KOSTL(01)'. PERFORM bdc_field USING 'BDC_OKCODE' '=BACK'. PERFORM bdc_field USING 'VFKN-SAKTO(01)' wa_zshpcst_h-saknr. PERFORM bdc_field USING 'VFKN-KOSTL(01)' wa_zshpcst_h-kostl.

PERFORM bdc_dynpro USING 'SAPMV54A' '0040'. PERFORM bdc_field USING 'BDC_OKCODE' '=PABR'.

PERFORM bdc_dynpro USING 'SAPMV54A' '0042'. PERFORM bdc_field USING 'BDC_OKCODE' '/00'. PERFORM bdc_field USING 'BDC_CURSOR' 'VFKPD-SLFREI'. PERFORM bdc_field USING 'VFKPD-SLFREI' 'X'.

PERFORM bdc_dynpro USING 'SAPMV54A' '0040'. PERFORM bdc_field USING 'BDC_OKCODE' '=SICH'.

PERFORM bdc_transaction USING 'VI01'.

PERFORM close_group.

It hits '=PABR' and drops out of BDC mode no mater what I do. It also doesn't transfer the 'X' into VFKPD-SLFREI. Anyone have any thoughts on what could be going wrong? Is there something else I should be doing to issue the transfer?