Forum error when i do upgrade
 

Database error in vBulletin 4.0.0 Alpha 6:

Invalid SQL:
ALTER TABLE attachment ADD INDEX contenttypeid (contenttypeid,contentid,attachmentid);

MySQL Error : Key column 'contenttypeid' doesn't exist in table
Error Number : -1
Request Date : Tuesday, January 5th 2010 @ 04:44:43 PM
Error Date : Tuesday, January 5th 2010 @ 04:44:43 PM
Script : ***********/install/upgrade_400b1.php?step=1
Referrer :***********//install/upgrade_400b1.php
Username :
Classname : vB_Database
MySQL Version :