My QuickBooks just updated to R12, and it seems that one of the data fields as inserted in the layout editor is not showing in on the final invoice, or the preview. It just leaves an empty space.
The field in question is the "Customer Contact" field, which contains the contact person of the customer.
Even weirder is this: if I define a custom field for a "Primary Contact Person" and insert it onto the invoice, it also does not show.
Perhaps it has something to do with too many items on an invoice? (Though, I doubt that - it wouldn't make any sense...)