I have two sites that share user tables.

The first (master) site uses all of its own tables. The second (slave) site uses its own tables and then the following from master: users, users_roles, sessions, roles, authmap, profile_fields and profile_values. The slave site has the following in its settings.php: 

$db_prefix = array(
 'default'   => 'slave.',
 'users'     => 'master.',
 'users_roles' => 'master.',
 'sessions'  => 'master.',
 'role' => 'master.',
 'authmap'   => 'master.',
 'profile_fields' => 'master.',
 'profile_values' => 'master.',
);

Everything works like it was explained in this article, however now CCK fields will not accept any new data on the slave site. I can create a new node which has required CCK data, but none of the CCK data gets saved in the database.

Has anyone else had an issue with multisite setups and CCK?