[Plugin: Simple Local Avatars] Undefined property errors on admin side of custom posts when plugin a

Having the same problem with WordPress 3.5.1, Simple Local Avatars 1.3.1 and one of several custom post types.

The errors appear only with one custom post type.

The errors appear if I log in as Author or Contributor, but not if I login as Administrator or Editor role.

The errors appear at <div id="wpcontent"> right before <div id="wpadminbar"...>

The local avatar in admin-bar is displayed fine.

Note: Contributor has upload rights via $role = get_role('contributor'); if ($role !== NULL) $role->add_cap('upload_files') in functions.php

Note 2: Setting simple_local_avatars_caps is not checked on WordPress Discussion settings page.

Notice: Undefined property: stdClass::$ID in ..wp-includes/query.php on line 3126

Notice: Undefined property: stdClass::$nickname in ..wp-includes/query.php on line 3128

Notice: Undefined property: stdClass::$user_nicename in ..wp-includes/query.php on line 3130

Notice: Undefined property: stdClass::$ID in ..wp-includes/query.php on line 3126

Notice: Undefined property: stdClass::$nickname in ..wp-includes/query.php on line 3128

Notice: Undefined property: stdClass::$user_nicename in ..wp-includes/query.php on line 3130

Any idea why?

The problem is triggered in line 88 in is_author() call:

$author_class = is_author( $user_id ) ? ' current-author' : '' ;

$user_id is a valid user id.

The error is not displayed if line 88 is changed e.g. like this:

1. Just “hide” the error:

$author_class = @is_author( $user_id ) ? ' current-author' : '' ;

2. Check for custom post type archive first, does this break other things?

$author_class = ( is_post_type_archive() || is_author( $user_id ) ) ? ' current-author' : '' ;