My schema's root is SalesCatalogue, which has 0 or more Product, which contains Name, Description, Price, ProductCode and Size.
When I created a data connection to this schema, then dragged the connection onto my form, the Name, Description, Price, ProductCode and Size fields appeared in the design view. They were enclosed in a Product subform. When viewing in the preview mode, the form displayed as blank.
When I unwrapped the Name, Description, Price, ProductCode and Size fields -- removed the Product subform, the fields appeared, and acted as I expected them to.
I am sure this makes perfect sense to the XML gurii, but I am posting this on the chance it will help some other novice.