4
i've only seen that problem occur after an upgrade to MySQL 4.1.x
something to do with the table collation & utf8
this thread may help:
https://xoops.org/modules/newbb/viewtopic.php?topic_id=29618&viewmode=flat&order=ASC&start=0
and also
https://xoops.org/modules/newbb/viewtopic.php?topic_id=29586&forum=27&post_id=130180#forumpost130180
altho it may not be the same issue.. but i'm sure it's to do with smarty not being able to write the templates to the DB.. check your MySQL permissions also as there's sometimes an issue with certain MySQL admin user accts not being able to write to the sql/tmp folder on the server..