dovecot - Apr 2008 - Plugin trash does not work

Hi.

I use dovecot 1.0.13 on FreeBSD 7.0. I want my Junk mail will be deleted 
if my quota is exceeded. So, I configured trash plugin (with Dovecot 
wiki). In my dovecot.conf:
protocol imap {
   mail_plugins = quota trash
}

plugin {
   trash = /usr/local/etc/dovecot-trash.conf
}

In my /usr/local/etc/dovecot-trash.conf:
1 Junk
2 Trash

Emails in there mailboxes are never deleted.

My mailbox is like this:
.Junk                      dovecot-uidlist           dovecot.index.log.2 tmp
.Trash                    dovecot.index            maildirsize
cur                         dovecot.index.cache  new
dovecot-keywords    dovecot.index.log       subscriptions

I want my .Junk directory be emptied when quota is exceeded.
May i forgot something? Could you help me?

Thanks very much!

  - Nicolas.