Last modified: 2012-02-21 10:03:20 UTC
For private wikis, /w/thumb.php gets called via https://secure.wikimedia.org/ instead of via upload.wm.o. Unfortunately, secure.wm.o directs these requests to regular app servers instead of the image scalers.
We have made available HTTPS for all wiki and secure.wikimedia.org is now obsolete rendering this bug obsolete too.