There are reports everywhere of uploading new versions of images failing (upload works but new version does not show up).
Last time this happened all that needed to be done was fot varnishhtcpd to be restarted on the image cache servers. [1] could someone with the ability to check, check if that needs to be done again? Imho this type of issue is a rather serious one which causes lots of frustration and confusion.
[1] https://bugzilla.wikimedia.org/show_bug.cgi?id=41130
-bawolff