Courier-imap with Postfix: folders don't work correctly

[Carl Fink <carlf@fink.to>]

I've had Postfix working fine on a server I run for months now.  For
all that time, 100% of mail was forwarded to other SMTP servers for
actual delivery.  I'm trying (at user request) to create actual mail
storage on the host for IMAP use.

I told Postfix to use maildir, installed courier-imap, followed the
configuration script, and mail is delivered to the Maildir in each
user's account, and can be read using Mozilla-Thunderbird.  However,
folders can only be created *inside* the inbox, which presents a
slight problem.  One of my users (who's also a programmer) says he's
heard that this can only be fixed by manually creating symlinks
inside Maildir to /var/spool/mail or something like that, which
strikes me as unlikely.

Any Postfix/Courier gurus out there with a few minutes to help a
poor, confused new Courier user? 

>From /etc/postfix/main.cf:
    mail_spool_directory = $HOME/Maildir
    home_mailbox=Maildir/

I don't know what part of the Courier config files is relevant, I'm
too new.

Thanks for any help.
-- 
Carl Fink             carl@fink.to        
Jabootu's Minister of Proofreading
http://www.jabootu.com