I have a layout where I show several menu items in a popdown menu and then the choices in a second popdown menu that change to reflect the choice in the first menu (only in a find layout). This setup

I have a layout where I show several menu items in a popdown menu and then the choices in a second popdown menu that change to reflect the choice in the first menu (only in a find layout). This setup uses an external data table (i.e. a second file) that stores the choices in the first popdown linked to the choices in the second. It works like a charm if I am using FMP8.5 directly. However, when I use this through IWP it doesn't work at all. I make the choice in the first popup and the second remains unpopulated. The second file is marked as being shared, so I don't know why this isn't working? Any suggestions? TIA