Awhile after I upgraded to spamd 4.5.0_3 from ports I started seeing this message in /var/log/messages:
Jul 23 15:01:49 host1 spamd: /sbin/pfctl returned status 1
And this on the console:
pfctl: /dev/fd/8: Is a directory
I was running FreeBSD 7.2-p6 and I upgraded the machine to 8.1 and the problem magically went away.