note de http://www.dokuwiki.org/update_check
When upgrading your installation, it might happen that DokuWiki continues to show the update message, even though the number in conf/msg was increased by the upgrade. This is because DokuWiki caches already fetched messages for a day and will only refetch if the last modified timestamp of conf/msg is higher than the one of the cache file. To stop the outdated update message from showing you can simply:
La solution la plus simple, utiliser le plugin upgrade
Astuce pour faire des patches avec diff / patch (très utile pour toute sorte d'upgrades de programmes open source)
dwmaj