Last modified: 2008-01-12 05:57:51 UTC
As summary says, please see http://lists.wikimedia.org/mailman/private/checkuser-l/2007-September/000992.html.
I did about 40 checks a bit ago on itwiki, not all are logged.
This is still an issue, and afaik nobody figured out a distinctive pattern yet, which checks are permanently logged and which are not. It seems all checks are logged at first and stay in the log at least for some minutes/hours, but then random log entries disappear for some reason.
Just one example to point out the importance of this bug:
Yesterday we had an issue regarding de.wikipedia and a check that was run by a steward without any notice to the local community. This log entry is currently not visible any longer (as if the check was never made).
As internal cross-wiki transparency within the group of users with CU access is a core feature (keyword: "checks and balances"), I'm increasing severity and priority for this bug now.
This is definitely a problem. Me and another checkuser performed a series of checks which were logged, then a few hours later all of them were gone... then a few hours later, half of hers were back but all mine were still gone. It's really odd.
Fixed in r29527.