1. Open 4-3-1 Select Invoices to Pay.
2. Select the invoice and the credit.
3. Click File and Save.
4. Open 4-3-2 Pay Vendors.
5. Select the vendor.
6. Select Check from the Pay now by picklist.
7. Click Edit, Period from the menu.
8. Select the correct period.
9. Click Pay Vendors.
10. Select the report criteria and report form in the Report Printing window.
11. Select the Print $0 Checks box.
12. Click File, Print.
13. Enter the General Checking Account.
14. Enter or accept the Starting Check Number.
15. Enter the Check Date.
16. Click Print Checks. 
17. Verify that the check prints correctly.
18. Click Post all checks and Continue.
19. Click OK on the message "Check Posting is Complete".

I'm not able to print a zero dollar AP check for a vendor