Chroot explanation required

On previous vsftp installation I have activated “chroot_local_user=YES” in order to jail users to their own directories. This no longer works as I get “500 OOPS: vsftpd: refusing to run with writable root inside chroot()” and “500 OOPS: priv_sock_get_cmd” warnings unless I comment out the “chroot_local_user=YES” line.

The problem is that now users can go to all of my directories and I dont want that. How can I restrict users to their own directories with the latest vsftpd.