That sounds like a pretty good theory. Cache coherency is probably at the heart of this bug.
** Changed in: apt (Ubuntu) Importance: Untriaged => Low Status: Unconfirmed => Confirmed -- BADSIG while using apt-proxy https://launchpad.net/bugs/49132 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs