Temporary malfunction of image upload for some clients
Several clients have reported today problems uploading pictures to their websites. (Documents and other file types were being uploaded just fine)
Our investigation eventually traced this down to a particular web server (Thus this problem affected only a certain proportion of clients who happened to be routed to that server).
We have now removed this server from our server farm and all sites are being served by the remaining servers and problem is no longer present.
We apologize for any inconvenience.
Dmitry Buterin commented
We have rebooted the server in question which seems to have resolved the image upload problem on it so we have added it back to the server farm.