My Stock Listing by Category report is missing certain products & I cant work out why

[KB]

The report displays those products/barcodes that have a
- non-zero Region1 price, and
- non-zero PackCost value, and
- "Include this Product in Reports" (Reports_Active) is set to true.

If "Include this Product in Reports" option is checked, zero 'Region1' price or zero 'PackCost' value should be the reason why the product is not displayed. It does not matter if a product's category is empty (not set), the product should be listed with an empty category name.