I did my own testing and I can duplicate the problem. I have reported the issue. As soon as I hear back if this is a function that will return I will let you know. For now, you can refer to page 330 in the Advance Accounting menu, where is talks about the Invoice Detail option. There really is not a step by step however.
I can give you an overview.
1. Click on the other sales and expense reductions button 2. Enter the dollar amount owed 3. Select an account such as Custom Hire Income 4. When you check the option to use Invoicing Detail (when not billing for a real inventory item, maybe like Combine work) click into the Details box. Click the drop down and select Add/Edit. Select New. Enter a name such as Combine charge. Select a unit such as Acres and Record and Done. Then select this new detail from the drop down. Then enter the qty for the units and OK. 5. When you return to the original Record Income or Sales, from the how you paid section, you can select the Bill button. Enter a due date and OK. 6. Record the Transaction. 7. When printing the invoice - there is an option under the Allocation Details, place dot by Show Invoice Allocations. 8. Print the invoice.
It will now show what you are billing for - a charge unit and total cost, so they understand how you arrived at this cost.