dovecot - Dec 2007 - dovecot.index only gets updated in Root maildir Folder

version 1.0.rc15
(Newest Version available in Debian 4.0, newer version in testing tree requires 
new version libc...)

I got a procmail rule that moves mail from some senders to another folder, e.g. 
.archive.facebook/ . This works fine, the message appear in 
.archive.facebook/new if i "ls" that directory by shell. But
dovecot.index files
don't get updated, hence IDLE doesn't tell the client new mail arrived.
this
only happens if i click on the folder in thunderbird. like this, not even 
clicking on Thunderbird "Check mail" button shows me new Mail arrived.

Is this a common error in this version? would there any benefit if i self 
compiled a newer version regarding this issue?

Thanx

Config:
log_timestamp: %Y-%m-%d %H:%M:%S
ssl_listen: *
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/imap-login
mail_extra_groups: mail
mail_location: maildir:~/Maildir
auth default:
   mechanisms: plain login
   passdb:
     driver: pam
   userdb:
     driver: passwd
   socket:
     type: listen
     client:
       path: /var/spool/postfix/private/auth
       mode: 432
       user: postfix
       group: postfix
     master:

Debian uses dnotify by default.