I have this same problem. I tried it on a bunch of random packages and none of them will lock.
Installed Synaptic package: synaptic-0.57.11 About version: 0.57.8 -- 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
