[Dovecot] Sieve Frustrations

[Shawn]

I'm soooo close, but this last little thing is eluding me...

I have the following Sieve rule in my global sieve rule:

require ["fileinto"];
# Move spam to spam folder
if header :contains "X-Spam-Flag" "YES" {
   fileinto "Junk";
   stop;
}

This isn't firing.  The .Junk folder exists under the user directories, 
but messages that have the X-Spam-Flag set are still going into INBOX.

My personal Sieve rules are firing properly (now), so I know Sieve is 
operational.  Just the global rule isn't being applied.

If it helps, I set up my server according 
http://workaround.org/articles/ispmail-etch/ - but on a Ubuntu Gutsy 
server with only a few minor deviations from that article.

My protocol lda section of dovecot.conf has this:
   log_path = /home/vmail/dovecot-deliver.log
   global_script_path = /home/vmail/globalsieverc

I don't see any messages in dovecot-deliver.log that says there are 
problems with Sieve.  The above rule is in /home/vmail/globalsieverc as 
mentioned here.  This was working once - but when I had it going into 
the "spam" folder.  I changed the folder name to match what ThunderBird 
sets up automagically for it's junk controls.  But like I say, the 
directory does exist.  So, I'm a little stumped.

Any suggestions on where I can look to sort this out?  If it helps, I've 
attached my dovecot conf (via dovecot -n) below.

Thank you for your time!

Shawn


root at mail:~# dovecot -n
# 1.0.5: /etc/dovecot/dovecot.conf
log_timestamp: %Y-%m-%d %H:%M:%S
protocols: imap imaps pop3 pop3s
ssl_cert_file: /etc/ssl/certs/dovecot.pem
ssl_key_file: /etc/ssl/private/dovecot.pem
login_dir: /var/run/dovecot/login
login_executable(default): /usr/lib/dovecot/imap-login
login_executable(imap): /usr/lib/dovecot/imap-login
login_executable(pop3): /usr/lib/dovecot/pop3-login
mail_extra_groups: mail
mail_location: maildir:/home/vmail/%d/%n
mail_executable(default): /usr/lib/dovecot/imap
mail_executable(imap): /usr/lib/dovecot/imap
mail_executable(pop3): /usr/lib/dovecot/pop3
mail_plugin_dir(default): /usr/lib/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap
mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3
pop3_uidl_format(default):
pop3_uidl_format(imap):
pop3_uidl_format(pop3): %08Xu%08Xv
auth default:
   mechanisms: plain login
   passdb:
     driver: sql
     args: /etc/dovecot/dovecot-sql.conf
   userdb:
     driver: passwd
   userdb:
     driver: static
     args: uid=5000 gid=5000 home=/home/vmail/%d/%n allow_all_users=yes
   socket:
     type: listen
     client:
       path: /var/spool/postfix/private/auth
       mode: 384
       user: postfix
       group: postfix
     master:
       path: /var/run/dovecot/auth-master
       mode: 384
       user: vmail