Payment Request set up

We are beginning the process to upgrade to PeopleSoft 9.2.  I am looking at the payment request feature.  I have set up a payment request template according to the information in AP_92_Payment_Request_Doclet.pdf.  When I try to enter a Payment Request, I keep getting the error message "Invalid Business Unit BUY01. Please select a valid Business Unit from the list."  Of course all of the Business Units are in the drop down list so I don't know what might be a valid one to use.  But any the I select give me the same error.  The set up is the same