I know ACP supports filtering by Author, but I don’t have that option for my Author column (I can still enable sorting or editing, though). Screenshot: http://take.ms/HalFM

I’m using User Role Editor plugin to modify user roles but have the same issue even with it deactivated.

I have a feeling it has something to do with a function I used to change the names of my user levels (from Subscriber to Client, Author to Inspector, etc.)

Do you think that’s why my Author filter isn’t available?
Is there any way to allow filtering by Author even after I’ve run this function?:

// CHANGE USER ROLE NAMES (CHANGES NAME IN DB, ONLY NEEDS TO RUN ONCE)
/*
function change_role_name() {
    global $wp_roles;

    if ( ! isset( $wp_roles ) )
        $wp_roles = new WP_Roles();

    //You can list all currently available roles like this...
    //$roles = $wp_roles->get_names();
    //print_r($roles);

    // options: administrator, editor, author, contributor, subscriber
    $wp_roles->roles['subscriber']['name'] = 'Client';
    $wp_roles->role_names['subscriber'] = 'Client';
}
add_action('init', 'change_role_name');
*/

// DELETE ROLE (CHANGES DB, ONLY NEEDS TO RUN ONCE)
// options: administrator, editor, author, contributor, subscriber
// remove_role( 'contributor' );