Milter-greylist

I'm new to milter-greylist and trying to get the DNSRBL support
working on OpenBSD 3.9 with the latest milter-greylist snapshot
(3.0-rc5).  Has anyone been able to get this to work successfully? 
Trying with just plain "--enable-dnsrbl --with-thread-safe-resolver",
I get the following compile errors:

gcc -g -O2 -Wall -DUSE_DNSRBL -D_BSD_SOURCE   -c -o milter-greylist.o
milter-greylist.c
gcc -g -O2 -Wall -DUSE_DNSRBL -D_BSD_SOURCE   -c -o pending.o pending.c
gcc -g -O2 -Wall -DUSE_DNSRBL -D_BSD_SOURCE   -c -o sync.o sync.c
gcc -g -O2 -Wall -DUSE_DNSRBL -D_BSD_SOURCE   -c -o dnsrbl.o dnsrbl.c
dnsrbl.c: In function `dnsrbl_check_source':
dnsrbl.c:109: error: syntax error before "handle"
dnsrbl.c:167: warning: implicit declaration of function `ns_initparse'
dnsrbl.c:167: error: `handle' undeclared (first use in this function)
dnsrbl.c:167: error: (Each undeclared identifier is reported only once
dnsrbl.c:167: error: for each function it appears in.)
dnsrbl.c:173: warning: implicit declaration of function `ns_msg_count'
dnsrbl.c:173: error: `ns_s_an' undeclared (first use in this function)
dnsrbl.c:174: warning: implicit declaration of function `ns_parserr'
dnsrbl.c:174: error: `rr' undeclared (first use in this function)
gmake: *** [dnsrbl.o] Error 1


That's not surprising, as OBSD's headers and libraries don't have an
ns_msg structure.  I then proceeded to install libbind 9.2.3p1 from
OBSD's ports tree.  After modifying the Makefile to get gcc to look to
libbind's header files instead of the stock OBSD header files, I got
milter-greylist to build:

CFLAGS=        -nostdinc -I/usr/local/bind/include -I/usr/include
-I/usr/local/include -g -O2 -Wall -DUSE_DNSRBL -D_BSD_SOURCE
LDFLAGS=
LIBS=            -lpthread -lmilter /usr/local/lib/libbind.a

(I selected the static library instead of the shared library based on
the comments in the README file included with 3.0.rc5.) 
Unfortunately, when milter-greylist executed, I got these ominous
warnings:

$ ./milter-greylist -v -D -u smmsp -p
/var/milter-greylist/milter-greylist.sock
./milter-greylist:/usr/lib/libc.so.39.0: ./milter-greylist : WARNING:
symbol(__p_class_syms) size mismatch, relink your program
./milter-greylist:/usr/lib/libc.so.39.0: ./milter-greylist : WARNING:
symbol(_res) size mismatch, relink your program
./milter-greylist:/usr/lib/libc.so.39.0: ./milter-greylist : WARNING:
symbol(__p_type_syms) size mismatch, relink your program
loading config file "/etc/mail/greylist.conf"
load peer dogbert
[...]

and eventually it segfaulted during testing (my milter-greylist that
was compiled without DNSRBL support ran fine during the same test).

Does anyone have any tips on how to get DNSRBL working on OpenBSD? 
I'd love to be able to use this feature.

Thanks in advance,

Erick.