http://lists.wikimedia.org/pipermail/mediawiki-announce/2010-March/000088.ht...
Which was also cross-posted to this list and wikitech-l.
Thank you, Chad, but what I actually wanted was an explanation of the bug. If the problem are external images, I presume a link has to be given somehow, but in our wiki only wiki-like links (ie, [http://...]) are allowed, so I was interested in the details. I presume the fix is this one:
http://svn.wikimedia.org/viewvc/mediawiki?view=rev&revision=63424
Javier