I just noticed that after upgrading to the latest code in CVS which mostly included the new Blog feature modifications, all the space-page relations are deleted! Looking at the local database, the entire "SpaceID" field value in "Content" table is NULL. And it's causing a lot of problems...

Deleting the whole config and starting from scratch is all fine and the new pages and spaces getting created have the relation there and all correct! So the only problem is with old data already in db.