Upgrade from D7 does not remove users field from comment table.

When upgrading from D5 to D6 to D7, column users in comment table is left behind. Simply removing it solved the following error. I am not sure if upgrade scripts should ensure it is gone or not.

PDOException: SQLSTATE[HY000]: General error: 1364 Field 'users' doesn't have a default value: INSERT INTO {comment} (pid, nid, uid, subject, hostname, created, changed, status, thread, name, mail, homepage, language) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6, :db_insert_placeholder_7, :db_insert_placeholder_8, :db_insert_placeholder_9, :db_insert_placeholder_10, :db_insert_placeholder_11, :db_insert_placeholder_12); Array ( [:db_insert_placeholder_0] => 9454 [:db_insert_placeholder_1] => 18 [:db_insert_placeholder_2] => 1 [:db_insert_placeholder_3] => Parandatud [:db_insert_placeholder_4] => 127.0.0.1 [:db_insert_placeholder_5] => 1317670142 [:db_insert_placeholder_6] => 1317670142 [:db_insert_placeholder_7] => 1 [:db_insert_placeholder_8] => 01.00/ [:db_insert_placeholder_9] => drupal6 [:db_insert_placeholder_10] => [:db_insert_placeholder_11] => [:db_insert_placeholder_12] => und ) funktsioonis drupal_write_record() (rida 6868 / /home/mattias/Veeb/master/includes/common.inc).