Last modified: 2006-10-16 19:14:31 UTC
When I uploaded a new image for http://en.wikipedia.org/wiki/Source_code (http://en.wikipedia.org/wiki/Image:Java_source2.png), it refuses to purge the thumbnail.
The Squids receive a fair amount of HTCP purge packets containing the URL: HEAD Array HTTP/1.0 So my theory is that there's a bug in MediaWiki where it doesn't properly handle arrays containing multiple purge URLs, as could be the case where thumbnails are involved.
Fixed in r17054.