我的天啊!刚刚想通了!正确的是,您必须在您的商品中添加另一个商品作为折扣。困难的部分是让小/总计正确!
这是我的SUCCESS提交:
array(14) {
    //  ERROR AREA 1    //  Total Amount of Items (including -Discount) and shipping and tax
    ["PAYMENTREQUEST_0_AMT"]
            =>  string(4) "9.71"
    //  ERROR AREA 2    //  Total Amount of items ONLY, including the -Discount!
    ["PAYMENTREQUEST_0_ITEMAMT"]
            =>  string(4) "6.76"
    ["PAYMENTREQUEST_0_SHIPPINGAMT"]
            =>  string(4) "2.95"
    ["PAYMENTREQUEST_0_TAXAMT"]
            =>  string(1) "0"
    /*  ITEMS   */
        /*  ITEM 01 */
    ["L_PAYMENTREQUEST_0_NAME0"]
            =>  string(18) "Order # 987654"
    ["L_PAYMENTREQUEST_0_AMT0"]
            =>  float(12.51)
    ["L_PAYMENTREQUEST_0_NUMBER0"]
            =>  string(6) "987654"
    ["L_PAYMENTREQUEST_0_QTY0"]
            =>  float(1)
    ["L_PAYMENTREQUEST_0_ITEMCATEGORY0"]
            =>  string(8) "Physical"
        /*  ITEM 02 */
        /*  ¡THE DISCOUNT!  */
    ["L_PAYMENTREQUEST_0_NAME1"]
            =>  string(9) "PromoCode"
    ["L_PAYMENTREQUEST_0_AMT1"]
            =>  float(-5.75)
    ["L_PAYMENTREQUEST_0_NUMBER1"]
            =>  string(18) "Promo 123456"
    ["L_PAYMENTREQUEST_0_QTY1"]
            =>  float(1)
    ["L_PAYMENTREQUEST_0_ITEMCATEGORY1"]
            =>  string(8) "Physical"
}
成功!
array(6) {
    ["TOKEN"]
        =>  string(20) "NOTIMPORTANT"
    ["TIMESTAMP"]
        =>  string(20) "2014-10-03T12:39:06Z"
    ["CORRELATIONID"]
        =>  string(12) "NOTIMPORTANT"
    ["ACK"]
        =>  string(7) "SUCCESS"
    ["VERSION"]
        =>  string(2) "93"
    ["BUILD"]
        =>  string(8) "13154493"
}
  是的,我知道这个问题很老,但我在其他任何地方都找不到答案。所以这是我的工作解决方案!