What is wrong with this SOP Payment?

Good morning,

I have SOP Sales Invoice of which already exists in the system totaling $30.00 with no payment applied having SOPNUMBE = INV00000000000037.

I would like to apply an SOP Payment of $30.00 to this existing invoice.  I have tried taCreateSopPaymentInsertRecord_Items with an <Action> = 1 (New Transaction) of which results in error 56 "taSopHdrIvcInsert , Input variable contains a duplicate document" and I have tried <Action> = 2 (Modify Existing) of which results in in error 3767 "taCreateSopPaymentInsertRecord, Payment does not exist".  Do I need to create a new SOP Document Number for the  taSopHdrIvcInsert requirement of the SOP Payment transaction?

Here is the XML for the two calls mentioned above:

[Action = 1]

<?xmlversion="1.0"encoding="utf-16"?>
<eConnectxmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <SOPTransactionType>
    <eConnectProcessInfoxsi:nil="true" />
    <taRequesterTrxDisabler_Itemsxsi:nil="true" />
    <taUpdateCreateItemRcdxsi:nil="true" />
    <taUpdateCreateCustomerRcdxsi:nil="true" />
    <taCreateCustomerAddress_Itemsxsi:nil="true" />
    <taSopSerial_Itemsxsi:nil="true" />
    <taSopLotAuto_Itemsxsi:nil="true" />
    <taSopLineIvcInsert_Itemsxsi:nil="true" />
    <taSopLineIvcInsertComponent_Itemsxsi:nil="true" />
    <taSopTrackingNum_Itemsxsi:nil="true" />
    <taSopCommissions_Itemsxsi:nil="true" />
    <taSopLineIvcTaxInsert_Itemsxsi:nil="true" />
    <taCreateSopPaymentInsertRecord_Items>
      <taCreateSopPaymentInsertRecord>
        <SOPTYPE>3</SOPTYPE>
        <SOPNUMBE>INV00000000000037</SOPNUMBE>
        <CUSTNMBR>VER002</CUSTNMBR>
        <CUSTNAME>Ted Bundy</CUSTNAME>
        <DOCDATE>04-03-2013</DOCDATE>
        <DOCAMNT>30.00</DOCAMNT>
        <AUTHCODE>ABC123</AUTHCODE>
        <PYMTTYPE>4</PYMTTYPE>
        <Action>1</Action>
        <USRDEFND1>This is a test</USRDEFND1>
      </taCreateSopPaymentInsertRecord>
    </taCreateSopPaymentInsertRecord_Items>
    <taSopUserDefinedxsi:nil="true" />
    <taSopDistribution_Itemsxsi:nil="true" />
    <taAnalyticsDistribution_Itemsxsi:nil="true" />
    <taSopMultiBin_Itemsxsi:nil="true" />
    <taSopHdrIvcInsert>
      <SOPTYPE>3</SOPTYPE>
      <DOCID>STDINV</DOCID>
      <SOPNUMBE>INV00000000000037</SOPNUMBE>
      <DOCDATE>04-03-2013</DOCDATE>
      <CUSTNMBR>VER002</CUSTNMBR>
      <CUSTNAME>Ted Bundy</CUSTNAME>
      <SUBTOTAL>30.00</SUBTOTAL>
      <PYMTRCVD>30.00</PYMTRCVD>
      <BACHNUMB>DONTEST</BACHNUMB>
    </taSopHdrIvcInsert>
    <taSopToPopLinkxsi:nil="true" />
    <taSopUpdateCreateProcessHoldxsi:nil="true" />
    <taCreateSOPTrackingInfoxsi:nil="true" />
    <taMdaUpdate_Itemsxsi:nil="true" />
  </SOPTransactionType>
</eConnect>

[Action = 2]

<?xmlversion="1.0"encoding="utf-16"?>
<eConnectxmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <SOPTransactionType>
    <eConnectProcessInfoxsi:nil="true" />
    <taRequesterTrxDisabler_Itemsxsi:nil="true" />
    <taUpdateCreateItemRcdxsi:nil="true" />
    <taUpdateCreateCustomerRcdxsi:nil="true" />
    <taCreateCustomerAddress_Itemsxsi:nil="true" />
    <taSopSerial_Itemsxsi:nil="true" />
    <taSopLotAuto_Itemsxsi:nil="true" />
    <taSopLineIvcInsert_Itemsxsi:nil="true" />
    <taSopLineIvcInsertComponent_Itemsxsi:nil="true" />
    <taSopTrackingNum_Itemsxsi:nil="true" />
    <taSopCommissions_Itemsxsi:nil="true" />
    <taSopLineIvcTaxInsert_Itemsxsi:nil="true" />
    <taCreateSopPaymentInsertRecord_Items>
      <taCreateSopPaymentInsertRecord>
        <SOPTYPE>3</SOPTYPE>
        <SOPNUMBE>INV00000000000037</SOPNUMBE>
        <CUSTNMBR>VER002</CUSTNMBR>
        <CUSTNAME>Ted Bundy</CUSTNAME>
        <DOCDATE>04-03-2013</DOCDATE>
        <DOCAMNT>30.00</DOCAMNT>
        <AUTHCODE>ABC123</AUTHCODE>
        <PYMTTYPE>4</PYMTTYPE>
        <Action>2</Action>
        <USRDEFND1>This is a test</USRDEFND1>
      </taCreateSopPaymentInsertRecord>
    </taCreateSopPaymentInsertRecord_Items>
    <taSopUserDefinedxsi:nil="true" />
    <taSopDistribution_Itemsxsi:nil="true" />
    <taAnalyticsDistribution_Itemsxsi:nil="true" />
    <taSopMultiBin_Itemsxsi:nil="true" />
    <taSopHdrIvcInsert>
      <SOPTYPE>3</SOPTYPE>
      <DOCID>STDINV</DOCID>
      <SOPNUMBE>INV00000000000037</SOPNUMBE>
      <DOCDATE>04-03-2013</DOCDATE>
      <CUSTNMBR>VER002</CUSTNMBR>
      <CUSTNAME>Ted Bundy</CUSTNAME>
      <SUBTOTAL>30.00</SUBTOTAL>
      <PYMTRCVD>30.00</PYMTRCVD>
      <BACHNUMB>DONTEST</BACHNUMB>
    </taSopHdrIvcInsert>
    <taSopToPopLinkxsi:nil="true" />
    <taSopUpdateCreateProcessHoldxsi:nil="true" />
    <taCreateSOPTrackingInfoxsi:nil="true" />
    <taMdaUpdate_Itemsxsi:nil="true" />
  </SOPTransactionType>
</eConnect>

Any help in understanding this would be greatly appreciated.  If you can provide a working XML sample that properly demonstrates appling an SOP Payment to an existing SOP Sales Invoice...you will be rained with praise.

Thanks,

Don