Malte,
for the package object itself I believe context_id should be set to be the closest ancestor package_id in the site map. I've enhanced site_node::instantiate_and_mount to default context_id to be exactly this and this is the behaviour you get if you use the site map UI.
For acs objects within the package I think they should have context_id be the package_id (directly or indirectly, indirect example being that the object is a posting in a forum and the forum has context_id=package_id).
If someone wants to examine the packages create scripts and fix any context_id inconsisetencies and provide a patch for it I think that would be quite appreciated.
