I have four users with the same version of PL/SQL Developer (7.0.3.1123 09.25249) on their PC two can open and view the contents of the "Materialized Views" folder and two cannot. All four users connect to the same Oracle database with the same ID/Password. This problem only occurs when connected to a production database (higher security). When connected to a development database (less secure) all four users are able to view the contents of the "Materialized views" folder.