2010/9/23 Brion Vibber brion@pobox.com:
(If using memcached, be sure to clear those out, reinitialize, or otherwise do something that forces old values to be cleared or ignored.)
$wgCacheEpoch is a good one for this. The easiest way to change it is to touch LocalSettings.php.
Roan Kattouw (Catrope)