Huh,  I went back in today to run the invoice list that I thought had the paid date associated with it, but you're right - it doesn't work.  I'm not sure whether what I did was get a view and not a report, of if the "paid date" was actually visible for invoices but it's not there now.  I'll provide feedback, again, but I know this has got to be doable since there is a related table somewhere otherwise you wouldn't be able to click on the invoice number and see the paid date on a window that slides in from the right.  

QB:  all we want is the ability to display invoice create date and invoice paid date on the same line in a report that could be grouped by customer, but doesn't have to be.