[Exim] Procmail config problems

Hi all-
I am trying to setup Exim 4.0.5 to pipe through procmail to allow for
some scripts I am running to quarantine spam messages. Any help someone
could provide would be greatly appreciated. I am receiving the following
error:

Sep 11 22:25:41 MAC exim[2433]: 2002-09-11 22:25:41 H2B02S-0001VK-00 **
mikec@??? <mike@???> R=procmail T=procmail_pipe: Child
process of procmail_pipe transport returned 127 from command:
/usr/bin/procmail
Sep 11 22:25:41 MAC exim[2443]: 2002-09-11 22:25:41 H2B02T-0001VV-00 <=
<> R=H2B02S-0001VK-00 U=exim P=local S=1978
Sep 11 22:25:41 MAC exim[2433]: 2002-09-11 22:25:41 H2B02S-0001VK-00
Completed

My Exim configuration is:

procmail:
    driver = accept
    check_local_user
    transport = procmail_pipe

procmail_pipe:
    driver = pipe
    command = /usr/bin/procmail
    return_path_add
    delivery_date_add
    envelope_to_add
    check_string = "From "
    escape_string = ">From "
    user = $local_part
    group = mail

Procmailrc looks like this:
# recover quarantine messages
:0
*^TO quarantine
| /usr/local/sbin/spam_rec

# email pushed by the quarantine recovery are delivered immediately
:0 :
* ^From quarantine@???
$DEFAULT

# do not check the summary messages
:0 :
* ^From root
* ^Subject: Quarantined messages
* ^Reply-To: quarantine@???
$DEFAULT

# check one message with spamc/spamd
:0fwE
| /usr/local/bin/spamc -u $LOGNAME

:0e
{
    EXITCODE=$?
}

DATE=`date +%Y%m%d%H%M`
PID=`echo $$`
SPAMFILE=$DEFAULT-spam.$DATE.$PID

# quarantine in /var/mail/user-spam.date.pid
:0:
* ^X-Spam-Status: Yes
$SPAMFILE