Please fix a defect with Web Services and the PayablesPayment object as documented with defect number CR 69082. Essentially when using the GetPostedPayablesVendorPaymentsByKey method to retrieve the PayablesPayment object you will see the Payments object has sub objects of the different payment types all with empty fields. If you look in the GP UI at this Payment you will see that there is data that should be populating these fields for one of the various types of Payments (cash, check, and credit card).