When grabbing the product id's from a category where the is_anchor attribute is set we get the complete collection. Including products from underlying categories.
Question: How can we get a list/array of product id's for any given category id that has the is_anchor attribute set - where the collection contains only the real products from that category only (and not also products from underlying categories)
This is what we have to date. But I am sure this is not the fastest method.
$category = new Varien_Object(array('id'=>$_cat));
$positions = Mage::getResourceModel('catalog/category')->getProductsPosition($category);
$includeIDs = array_keys($positions);
Reference: Array of product ids for a given category (respecting is_anchor)