I don't know if it can help you to narrow down the search for the version of synaptic that is affected by this bug, but synaptic works fine for lock and unlock in Debian testing, which has the package synaptic-0.57.11(but the Help-About box shows version 0.57.8, go figure...).
-- Lock Version not working https://launchpad.net/bugs/63777 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
