archiving problem

I am trying to set up .procmailrc to archive it's own log via a monthly cron
job.

ARG = $1

:0
* ARG ?? archive
{
   :0
   {
      LOGDATE = `echo "$YYYY $MM" | perl -lane '--$F[1] or --$F[0] and 
$F[1]=12; printf "%d-%02d\n", @F'`
      ARCHIVE = "$LOGFILE.$LOGDATE"
   }

   LOG = "Archiving procmail log to $ARCHIVE$NL"

   :0 hwi
   * !
   | ( mv $LOGFILE $ARCHIVE ;\
       touch $LOGFILE       ;\
       chmod 400 $ARCHIVE )
}

However, when I test it

   jlloyd(_at_)hyperion:{~}:==> echo "" | procmail -a archive

the following appears in my log:

Archiving procmail log to /uhome/jlloyd/.procmail/pm.log.1998-09
Fixing empty Subject: header
Fixing non-existant Message-Id: header
> From foo(_at_)bar  Tue Oct 27 21:34:32 1998
 Subject: [empty]
  Folder: /uhome/jlloyd/mail/spool/mail/default                             100

I have found that putting

   :0
   /dev/null

at the bottom of the recipe results in only

Archiving procmail log to /uhome/jlloyd/.procmail/pm.log.1998-09
  Folder: /dev/null                                                           1

But why is anything getting delivered at all?

Justin

-- 
Justin C. Lloyd               Harris Corporation, ISD     Voice  407/984-5558
jlloyd(_at_)harris(_dot_)com             505 John Rodes Blvd.        Fax    
407/984-6323
Unix System Administrator     Melbourne, FL  32935        Office  W3/1811B