Brian, I've run into this issue several times. I'm going to assume CTD = COUNTD(). Jonathan Drummey spent more than an hour with me on a Google Hangout trying to get a COUNTD() on a secondary data source to work. And it only worked when we took several fields out of the viz that were actually needed. So in essence did never really got it to work. If you can post a package workbook with sample data, we can take a look and see if it's fixable.