[Mediawiki-l] user.user_editcount disagrees with revisions table - why?

[Daniel Barrett]

Recently I discovered that the user_editcount column in the "user" table disagrees with the actual edits in the "revisions" table by a significant amount. To fix this, I ran maintenance/initEditCount.php.  My question is: what causes these numbers to get out of sync in the first place?  Should I need to run this maintenance script regularly?

This is MediaWiki 1.16.2 on a single server with a single database. The wiki began its life at 1.10.0, if that matters.

Thanks,
DanB