PayPal显示空购物车

我有两个不同东西的付款页面。其中一个效果很好，可以像它应该的那样将购物车发布到PayPal，另一个则显示一个空的购物车。我已经查看了我发送到的url字符串，这些是唯一不同的参数：

作品：

&item_name_1=Add+Seats+-+Keynote+Manager
&item_number_1=Add+to+License
&amount_1=68
&quantity_1=1
&notify_url=http%3A%2F%2Frevolutiondesign.biz%2FIPNBroker.php%3Fkey%3DAZHJ0T1U05V1W1XY8G1C3C3XP3IMF2N2PP%26extendYears%3D0%26newSeats%3D1%26addPortable%3D%26newFeatures%3D
&custom=upgrade
&key=AZHJ0T1U05V1W1XY8G1C3C3XP3IMF2N2PP
&extendYears=0
&newSeats=1
&addPortable=
&addFeatures=
&qtyAddFeatures=0
&costAddFeatures=0
&qtyAddSeats=1
&costAddSeats=68
&qtyPortable=
&costPortable=
&qtyExtend=0
&costExtend=0
&v=63400

没有：

&item_name_1=Add+Cloud+Seats
&item_number_1=Add+Cloud+Seats
&amount_1=94
&quantity_1=1
&notify_url=http%3A%2F%2Frevolutiondesign.biz%2FIPNBroker.php%3FcustomerID%3Dba3d3c75-5e18-42b7-948e-3e34cccc1d9e%26extendPeriod%3Dmonths%26qtyExtend%3D1%26qtyAddSeats%3D1
&custom=cloudUpgrade
&cstID=ba3d3c75-5e18-42b7-948e-3e34cccc1d9e
&costAddSeats=97
&costExtend=7
&v=GREAT+Design+Group
&extend=1
&extendPeriod=months
&add=1

有人能看到会导致第二个不起作用的区别吗？