A proper workaround is probably to just do "sudo delgroup <username>" and then to re-add the user, altough editing /etc/groups will *probably* do the same.
-- [users-admin] Adding a previously existing user fails silently https://launchpad.net/bugs/66051 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
