... categories not showing up / products (not) showing up in some places?

1. categories must be subcategories of some (e.g. "Default") category
(-> Catalog -> Manage Categories)
2. parent category must be set as "Root Category" for store
(-> System -> Manage Stores -> [Store Name])


magento version:
1.6.1.0

date:
Mon Dec 12 15:21:10 CET 2011

sources:
http://www.aschroder.com/2009/03/top-3-solutions-when-your-magento-categories-are-not-displaying/