Attaching a proposed patch for apt-cacher-ng which seems to sort the problem out for me. This diff also includes a conversion to debian 3.0 (quilt) format so it is slightly bigger than required.
** Attachment added: "apt-cacher-ng-DevelReleaseAnnouncement" http://launchpadlibrarian.net/51410855/apt-cacher-ng-DevelReleaseAnnouncement -- update-manager fails to download release notes with apt-cacher-ng https://bugs.launchpad.net/bugs/601883 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs