[Mimedefang] Spamhaus on SA

[Al Sparks]

I have the following in my sa-mimedefang.cf file in /etc/mail/spamassassin:

  header RCVD_IN_SBL eval:check_rbl_txt('sbl', 'sbl.spamhaus.org.')
  describe RCVD_IN_SBL mm added
  tflags RCVD_IN_SBL net
  score RCVD_IN_SBL 5.0

I can't seem to get it to work however.  Test messages to spamhaus's auto
tester come back negative.

I'm running MD 2.43, and SA 2.64.  SA is working through MD, logs
show lots of spam is getting stopped (too much getting through though).

Is there a problem getting SA to use spamhaus if run through MD?
  === Al