Ordering of "Last Comment Time", "Last Comment Author" causes SQL cross-dependency

When I add the two fields in the order "Last Comment Author", then "Last Comment Time" in my table view, I get the error below in my logs. When I change their order, the view executes fine.

Cross dependency found in OUTER JOIN; examine your ON conditions query: views_build_view SELECT DISTINCT(node.nid), node.changed AS node_changed_changed, node.title AS node_title, node.changed AS node_changed, users.name AS users_name, users.uid AS users_uid, users2.name AS node_comment_statistics_name, node_comment_statistics.last_comment_name AS node_comment_statistics_last_comment_name, node_comment_statistics.last_comment_uid AS node_comment_statistics_last_comment_uid, node_comment_statistics.last_comment_timestamp AS node_comment_statistics_last_comment_timestamp FROM rpnode node INNER JOIN rpusers users ON node.uid = users.uid LEFT JOIN rpusers users2 ON node_comment_statistics.last_comment_uid = users2.uid LEFT JOIN rpnode_comment_statistics node_comment_statistics ON node.nid = node_comment_statistics.nid INNER JOIN rpnode_access na ON na.nid = node.nid WHERE (na.grant_view >= 1 AND ((na.gid = 0 AND na.realm = 'all') OR (na.gid = 0 AND na.realm = 'og_public') OR (na.gid = 29049 AND na.realm = 'og_subscriber'))) AND ( (node.type IN ('forum')) ) ORDER BY node_changed_changed DESC LIMIT 0, 5