Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 24754)
+++ wp-includes/post.php	(working copy)
@@ -2056,7 +2056,7 @@
 	$query = "SELECT post_status, COUNT( * ) AS num_posts FROM {$wpdb->posts} WHERE post_type = %s";
 	if ( 'readable' == $perm && is_user_logged_in() ) {
 		$post_type_object = get_post_type_object($type);
-		if ( !current_user_can( $post_type_object->cap->read_private_posts ) ) {
+		if ( $post_type_object && !current_user_can( $post_type_object->cap->read_private_posts ) ) {
 			$cache_key .= '_' . $perm . '_' . $user->ID;
 			$query .= " AND (post_status != 'private' OR ( post_author = '$user->ID' AND post_status = 'private' ))";
 		}