Drupal 5.5? I must have missed 5.4
While I was looking the other way, the good people behind the Drupal project went and released TWO updates. If you blinked, you probably missed the release of Drupal 5.4, which corrected a potential SQL injection vulnerability. The release was immediately followed (well, a day later) by Drupal 5.5 to correct a minor boo boo created with the previous update.