Tank Auth：帐户确认电子邮件激活码已过期

Question

当用户点击“完成注册”链接时，会显示The activation code you entered is incorrect or expired.
这是tank_auth配置：

$config['allow_registration'] = TRUE;
$config['captcha_registration'] = FALSE;
$config['email_activation'] = TRUE;
$config['email_activation_expire'] = 60*60*24*2;
$config['email_account_details'] = TRUE;

当我使用原始TA视图时工作正常。不知道在哪里以及如何调试。
Codeigniter v2.1.2，PHP 5