[ForceHSS]

Run this sql, I also uploaded the sql
This is from 4.1.12 I dont have 4.2 installed so check first to make sure no changes to that table before using

DROP TABLE IF EXISTS `discussion`;
CREATE TABLE `discussion` (
  `discussionid` int(10) unsigned NOT NULL auto_increment,
  `groupid` int(10) unsigned NOT NULL,
  `firstpostid` int(10) unsigned NOT NULL,
  `lastpostid` int(10) unsigned NOT NULL,
  `lastpost` int(10) unsigned NOT NULL,
  `lastposter` varchar(255) NOT NULL,
  `lastposterid` int(10) unsigned NOT NULL,
  `visible` int(10) unsigned NOT NULL default '0',
  `deleted` int(10) unsigned NOT NULL default '0',
  `moderation` int(10) unsigned NOT NULL default '0',
  `subscribers` enum('0','1') default '0',
  PRIMARY KEY  (`discussionid`),
  KEY `groupid` (`groupid`,`lastpost`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;