first, as a drupal developer of 6 years magento is unpolished, volatile, and extremely inconsistent. this simple ecommerce site has been nothing short of a train wreck /endrant
i have category called lighting with 4 child categories. if you click lighting in the menu the page never loads, it just sits. however, if you click one of the child categories it loads just fine. this is the case for other menu items too but not all. if i disable all product under category that won't load it loads just fine obviously displaying no product.
so now, any new categories i add to the default category, no matter hierarchy, as soon as i add 1 product to that category, it stops loading. great.