Due to the fact that I manually inserted data into db, I created the manufacturer entries and the used the guid field as manufacturer column value for each product. I suppose this is all I need to display the product manufacturer, but when I edit a product the manufacturer is set up as nothing and on the customer side, on product detail, the manufacturer isn't displayed at all.

Is there something more I've to do?

A select into the db, joining the fields, correctly returns value. So what's the matter?

Thanks
Andrea