[exim] Exiscan/spamassassin not rewriting subjects

I looked this up and can't see where I'm doing anything wrong, but the
subject is not being rewritten.

Some relevant data:

/etc/mail/spamassassin/local.cf

# How many hits before a message is considered spam. required_score 3.0

# Change the subject of suspected spam
rewrite_header Subject *****SPAM*****

Changing the required score value shows up in the mail headers.

/etc/sysconfig/spamassassin

SPAMDOPTIONS="-d -m5 -H/var/spool/spamd "



I elimininated the -c option because of the following errors.


Feb 18 20:24:59 WBServer spamd[18388]: info: setuid to nobody succeeded Feb
18 20:24:59 WBServer spamd[18388]: Creating default_prefs
[//.spamassassin/user_prefs] Feb 18 20:24:59 WBServer spamd[18388]: Cannot
write to //.spamassassin/user_prefs: No such file or directory Feb 18
20:24:59 WBServer spamd[18388]: Couldn't create readable default_prefs for
[//.spamassassin/user_prefs]


I'm not sure whether this has anything to do with the problem or not. I
don't see where the setuid to nobody comes from. I added the
/var/spool/spamd after the -H option and made spamd & the .spamassassin
subdirectory world writeable to see if this would eliminate the error but it
didn't.

From exiscan.conf
acl_check_content:

  # Reject virus infested messages.
#  deny  message = This message contains malware ($malware_name)
#        malware = *

# Messages larger than 200k are accepted without spam scanning to reduce
spamd load accept condition = ${if >{$message_size}{150k}{true}}

  # Always add X-Spam-Score and X-Spam-Report headers, using SA system- wide
settings
  # (user "nobody"), no matter if over threshold or not.
  warn  message = X-Spam-Score: $spam_score ($spam_bar)
        spam = sa:true
  warn  message = X-Spam-Report: $spam_report
        spam = sa:true

  # Add X-Spam-Flag if spam is over system-wide threshold
  warn message = X-Spam-Flag: YES
       spam = sa

  # Reject spam messages with score over 10, using an extra condition.
  deny  message = This message scored $spam_score points. Congratulations!
        spam = sa:true
        condition = ${if >{$spam_score_int}{100}{1}{0}}

##
# Rewrite subject if email scored between 5 and 10.
##

# For the subject tag, we prepare a new subject header in the # ACL, then
swap it with the original Subject in the system filter.
        warn message =    X-Exiscan-SA-New-Subject: ***SPAM***$h_subject

        

            condition = ${if >{$spam_score_int}{50}{1}{0}}

# finally accept all the rest
accept


SpamAssassin version is 3.0.1, perl is 5.8.5, Exim is 4.4.3, exiscan patch
is patch revision 28.