If the owner of the tables in the PG database and the db_user in the server config.tcl file (that is used to connect to the db with) do not match, no tables are displayed in the schema browser. There's also no indication to the user as to where all the tables "disappeared".
What's the practical purpose of that restriction? Any objection if I remove it. After all, the db_user has full permission on those tables or else OACS would not work, so I don't see why they should be hidden just because the owner does not match.