Last modified: 2008-03-28 19:53:25 UTC
If MediaWiki:Checkuser-log-subpage (the name of the CU log) contains spaces it will never work.
(I agree it requires lots of cluelessness to use a space in such strings. Still, somebody did that.)
May be related to bug#12669 or not...
More generally, it's completely and 100% broken and wrong. :)
But that's bug 12669... adding dep.
Fixed in r32554.