Add sub-domain DNS records to parent domain? doesn't work.

Hi
The Bind-Option

"Add sub-domain DNS records to parent domain?"

has no effect. Also with this option enabled, it will create a separate zone file instead of writing it to the parent file.
Joe describes, how it should work here:
http://www.virtualmin.com/forums/limit/10/limitstart/10/virtualmin/re%3a...