CustomerPayment being applied as the full amount

I've got a UE script that is transforming an Invoice into a CustomPayment.  I'm setting various fields on the payment record including 'payment'.

Although I have set the payment amount to something less than the full amount, when the record is saved it applies the full amount to the Invoice.

Here is the code (trimmed down sample)

 /*    *  This  script  will  handle  the  client  side  as  well  as  server  side  EOB  related  tasks   */   var CUST_PYMT_FLD  =   {        CUST                     : 'customer',        IDUNNO                   : 'undepfunds',        APLD                     : 'applied',        AUTO_APPLY               : 'autoapply',        CHKNUM                   : 'checknum',        PYMT_METHOD              : 'paymentmethod',        MEMO                     : 'memo',        PYMT                     : 'payment',        TRANDATE                 : 'trandate',   }       function  OnAfterSubmit(type)   {        try        {            var eobRecord =  nlapiGetNewRecord();                            var paymentRecord  = nlapiTransformRecord('invoice',  '9341',  'customerpayment');                        paymentRecord.setFieldValue(CUST_PYMT_FLD.CUST, '1032');            paymentRecord.setFieldValue(CUST_PYMT_FLD.PYMT, '200.0');            paymentRecord.setFieldValue(CUST_PYMT_FLD.CHKNUM, 'ABC123');            paymentRecord.setFieldValue(CUST_PYMT_FLD.PYMT_METHOD, '2');            paymentRecord.setFieldValue(CUST_PYMT_FLD.TRANDATE,  nlapiDateToString(new  Date())  );            paymentRecord.setFieldValue(CUST_PYMT_FLD.AUTO_APPLY, 'F');            paymentRecord.setFieldValue('department',  '2');                                    nlapiSubmitRecord(paymentRecord);        }        catch(err)        {            logException(err);        }   }