TOP N Algorithm in Product recommendation not working

While configuring Product Recommendations, we configured the TOPN Algorithm with a Custom Item data source (which contains a selected set of products), we did not change the Transaction or the User data sources.

We then generated the stored procedures, which updates the table PROD_D_TOPN, with the scores. However, in that table, we do not see the names of the products from our custom data source. As a result our Products do not show up in Product recommendation as well.

We haven't changed the data source for the transactions. What we want to do is to have recommendations coming from a limited set of Products. We do have Sales Orders in our system for that set of Products.

On a related note, what is the cleanup procedure on the algorithm used for?

Regards,

Ajit