[Dovecot] problems with migration to Maildir

[F. Even]

I'm attempting to use Maildir and mbox together until I can finish 
migrating all mailboxes and figure out issues I'm having with a couple 
other mailboxes.  But, I want to officially start using Maildir as the 
primary msg. store.  Now...when I configure Dovecot as follows, it 
creates new folders in the ~/mail folder, which is where my mboxes reside:

#default_mail_env =
#default_mail_env = mbox:~/mail/:INBOX=~/mbox
#default_mail_env = mbox:~/:INBOX=~/mbox
#default_mail_env = mbox:~/mail:INBOX=~/mbox
default_mail_env = maildir:~/Maildir

#namespace private {
#  separator = /
#  inbox = yes
#  prefix =
#  location = mbox:~/mail:INBOX=~/mbox
#}
#namespace private {
#  separator = /
#  prefix = "Maildir/"
#  location = maildir:~/Maildir
#}

namespace private {
   separator = /
   inbox = yes
   location = maildir:~/Maildir
}
namespace private {
   separator = /
   location = mbox:~/mail
}



I would like to have access to the mbox hierarchy, but I want all new 
folders by default created in ~/Maildir.  How do I go about acheiving this?

Thanks,
Frank