Orchard not saving custom type items

I've created a new content type, product.

And a products List.

When I save a new Product item, and select Products from the list, Orchard tells me that the product have been saved correctly, but oddly the [Add to] combo box turns back to None, and the Product isn't really saved anywhere.

If I list the items for the Product type, I se开发者_如何学Goe nothing. If I go to the Products page on the site, the content is empty.

What do I do wrong? thanks

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Sorry, I didn't add the Common content part. Now all works well.