In the 2.58 install zip file please verify that you have the following stored proc in the 01.00.03.SqlDataProvider file:

CREATE PROCEDURE {databaseOwner}{objectQualifier}Smith_ListFeaturedProducts
AS

SELECT * FROM {objectQualifier}Smith_Products
where logicallydeleted <> 1 and featured = 1
order by SortOrder , ModelName

GO

It should have been created when you ran the upgrade. Please verify the stored procedure is in the 01.00.03.SqlDataProvider file.

I am looking into why that stored proc in the would not run when installing over an existing cart module. The stored proc exists in the install script so thats not the issue it must be something with going on with that repair prompt you get when you try to install over a module that is already installed I dont think dnn is running the sql scripts in that case. It will require some more research, in the mean time you can try running that stored proc from sql mgmt studio or query analyzer to create the store proc that is missing.

Same behavior. Install was the same - only allowed a "Repair" install, but once run the module lists as v2.6. Featured products module still throws same error.

Can you try it with the featured products module on the same page as the smith.buynow module.