   user_active tinyint(1) default NULL,
   username varchar(50) NOT NULL default '',
   user_password varchar(32) NOT NULL default '',
-  user_session_time datetime NOT NULL default '0',
+  user_session_time timestamp default null,
   user_session_page smallint(5) NOT NULL default '0',
-  user_lastvisit datetime NOT NULL default '0',
-  user_regdate datetime NOT NULL default '0',
+  user_lastvisit timestamp default null,
+  user_regdate timestamp default null,
   user_level tinyint(4) default NULL,
   user_posts mediumint(8) NOT NULL default '0',
   user_timezone varchar(5) NOT NULL default '',

  topic_id mediumint(8) NOT NULL default '0',
  forum_id smallint(5) NOT NULL default '0',
  user_id mediumint(8) default NULL,
  post_time datetime default NULL,
  poster_ip varchar(15) default NULL,
  enable_bbcode tinyint(1) NOT NULL default '1',
  enable_html tinyint(1) NOT NULL default '1',
  enable_smilies tinyint(1) NOT NULL default '1',
  enable_sig tinyint(1) NOT NULL default '1',
  post_edit_time datetime default NULL,
  post_edit_count smallint(5) NOT NULL default '0',
  status tinyint(1) default '1',
  PRIMARY KEY  (post_id),

  topic_last_post_id mediumint(8) NOT NULL default '0',
  moderated smallint(1) default '0',
  session varchar(50),
  time timestamp,
  KEY  (topic_id),
  KEY (forum_id),
  KEY(user_id),
