Imported products missing from admin, but present for orders and front-end display

As part of a recent project, a PHP script was created that parses a standard file feed (UIEE) into the zen cart products database.

This works successfully, and populates both the znc_products and znc_products_description MySQL tables with the products. The products display great on the front-end, with products_status set at 1, and if you add them to the cart everything seems to work fine.

However, not a single product, other than a couple that were added manually, display when trying to find them in categories/products.

Has anyone else had this issue with batch importing, or is this a more complicated issue than some simple display hinderance?

I greatly appreciate any help in advance, as it's currently a project showstopper

v1.3.9h

Ok, probably a newbie mistake.

For each item imported, the product_id must be associated with records in znc_products, znc_products_description, and znc_products_to_categories.

After adding the znc_products_to_categories entries for the products, they displayed succesfully in the admin and front-end areas.