when adding an ecommerce item using an array of categories (as described @ docs/ecommerce-analytics/#toc-tracking-ecommerce-orders-items-purchased-required), the ecommerce product category report simply shows 'Array' as category.

when an order contains multiple ecommerce items of the same single category, the ecommerce product category report doesn't accumulate values from that order, but simply shows the value of the first item added for a specific category

using piwik 1.5.1