You don't want a new directory except for the first one, which makes the 'jails' dataset. After that they should just accumulate as part of the same dataset. I am not sure whether you then have to add "jails" to the destination path, or not.
Edit: as to why the automatic task doesn't work, I have no idea. All I know is it used to work in 9.3 before the latest update.
Edit: as to why the automatic task doesn't work, I have no idea. All I know is it used to work in 9.3 before the latest update.