Field 'signature' doesn't have a default value (seems to be conflict with signature forum module)

[English]
Such message after twice trying to login by VK service:

PDOException: SQLSTATE[HY000]: General error: 1364 Field 'signature' doesn't have a default value: INSERT INTO {users} (uid, name, pass, mail, created, access, status, init, data) 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); Array ( [:db_insert_placeholder_0] => 10 [:db_insert_placeholder_1] => ulogin_vkontakte_xxx [:db_insert_placeholder_2] => bla-bla [:db_insert_placeholder_3] => xxx@mail.ru [:db_insert_placeholder_4] => 1335642718 [:db_insert_placeholder_5] => 1335642718 [:db_insert_placeholder_6] => 1 [:db_insert_placeholder_7] => ulogin_vkontakte_xxx [:db_insert_placeholder_8] => a:2:{s:7:"contact";i:1;s:6:"ulogin";a:13:{s:12:"access_token";s:63:"xxx";s:7:"network";s:9:"vkontakte";s:8:"identity";s:23:"http://vk.com/idxxx";s:3:"uid";i:2088834;s:5:"email";s:15:"xxx@mail.ru";s:8:"nickname";s:5:"Alina";s:10:"first_name";s:10:"Алина";s:9:"last_name";s:14:"bla-bla";s:5:"bdate";s:10:"17.12.1987";s:3:"sex";i:1;s:5:"photo";s:50:"http://cs10494.userapi.com/uxxx/e_xxx.jpg";s:4:"city";s:12:"Казань";s:6:"manual";s:5:"email";}} ) в функции drupal_write_record() (строка 6975 в файле /home/u4370/domains/xxx.ru/includes/common.inc).

After disabled 'Signature forum' module and deleted itfrom DB there is no error.

And a little question (or just say to me, whether I should create new issue for this): after login by VK or Yandex, the username was like 'ulogin_vkontakte_idxxx' - is this what's written on module page in 'Installation and Setup' block at last item or any error?

Thank You!

[Русский]
Такое сообщение получил дважды при попытке войти через Вконтакте:

PDOException: SQLSTATE[HY000]: General error: 1364 Field 'signature' doesn't have a default value: INSERT INTO {users} (uid, name, pass, mail, created, access, status, init, data) 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); Array ( [:db_insert_placeholder_0] => 10 [:db_insert_placeholder_1] => ulogin_vkontakte_xxx [:db_insert_placeholder_2] => bla-bla [:db_insert_placeholder_3] => xxx@mail.ru [:db_insert_placeholder_4] => 1335642718 [:db_insert_placeholder_5] => 1335642718 [:db_insert_placeholder_6] => 1 [:db_insert_placeholder_7] => ulogin_vkontakte_xxx [:db_insert_placeholder_8] => a:2:{s:7:"contact";i:1;s:6:"ulogin";a:13:{s:12:"access_token";s:63:"xxx";s:7:"network";s:9:"vkontakte";s:8:"identity";s:23:"http://vk.com/idxxx";s:3:"uid";i:2088834;s:5:"email";s:15:"xxx@mail.ru";s:8:"nickname";s:5:"Alina";s:10:"first_name";s:10:"Алина";s:9:"last_name";s:14:"bla-bla";s:5:"bdate";s:10:"17.12.1987";s:3:"sex";i:1;s:5:"photo";s:50:"http://cs10494.userapi.com/uxxx/e_xxx.jpg";s:4:"city";s:12:"Казань";s:6:"manual";s:5:"email";}} ) в функции drupal_write_record() (строка 6975 в файле /home/u4370/domains/xxx.ru/includes/common.inc).

После того, как отключил модуль 'Signature forum' и удалил его из БД, ошибка пропала.

И еще небольшой вопросик (или просто напишите, создавать ли для описания этой ошибки новое ишью): после того, как залогиниваюсь через сервисы Вконтакте или Яндекс, имя аккаунта получается что-то вроде 'ulogin_vkontakte_idxxx' - это как раз то, что написано на странице описания модуля в блоке 'Installation and Setup' последним пунктом или какая ошибка?