We rely for an external project on XML/RPC access to a magento store. When we try to get the store's categories, we find, that url_path is missing for some categories (so we cannot link to these categories). on further investigation, we found out, that some categories have an empty url_path: http://screencast.com/t/lAtInv9U - we now wonder, how to fill this column.
we tried switching from flat to EAV model for categories (system->configuration->catalog->catalog->shop) with no success - the url_path column just doesn't get filled.
this is magento 1.7.0.0