The following query
on the test data produces 3 rows on 5.5.27 and 2 rows on 5.5.25. The correct result is 2 rows, which is obvious because the third row has node_uid which is neither 2084 nor 2085.
Reproducible with the default optimizer_switch as well as with all OFF values.
Reproducible with MyISAM, Aria, InnoDB.
Reproducible on MariaDB 5.5.27, MySQL 5.5.27, current maria/5.5 revno 3533.
Could not reproduce on MariaDB 5.5.25, MariaDB 5.3 revno 3576, MySQL 5.6.6.
EXPLAIN (with all OFF values in optimizer switch):