I can confirm this bug, too. And IMHO, it is a rather severe one. Caused me quite some trouble after moving an important DHCP server to Ubuntu :-/
-- Dnsmasq crashes when renewing non-existent lease https://launchpad.net/bugs/47438 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs