[Mediawiki-l] problem upgrading from 1.5.3 to 1.6.7

[Felipe Sanches]

MediaWiki 1.6.7 Updater

Going to run database updates for cee
Depending on the size of your database this may take a while!
Abort with control-c in the next five seconds...0
...hitcounter table already exists.
...querycache table already exists.
...objectcache table already exists.
...categorylinks table already exists.
...logging table already exists.
...validate table already exists.
...user_newtalk table already exists.
...transcache table already exists.
...trackbacks table already exists.
...externallinks table already exists.
Creating job table...Query "CREATE TABLE `wikicee_job` (
 job_id int(9) unsigned NOT NULL auto_increment,
 job_cmd varchar(255) NOT NULL default '',
 job_namespace int NOT NULL,
 job_title varchar(255) binary NOT NULL,
 job_params blob NOT NULL default '',
 PRIMARY KEY job_id (job_id),
 KEY (job_cmd, job_namespace, job_title)
 ) TYPE=InnoDB
" failed with error code "Specified key was too long. Max key length
is 500 (loc      alhost)".
cee at bighead:~/www/wiki/maintenance>

Can anybody help me?