Payflow Pro & Undefined symbol

Hello all, I'm running php 4.3.7, apache 1.3.29 and the Payflow Pro SDK v3.0.7 (amongst other things) all under FreeBSD 4.10. When I attempt to test the Payflow Pro functions in a test page (using the example 1 code at http://us4.php.net/manual/en/function.pfpro-process.php, changing the username and password as appropriate), I get the following message in my apache error log: /usr/libexec/ld-elf.so.1: /usr/local/lib/libpfpro.so: Undefined symbol "pthread_mutex_init" Something to do with Posix threads and shared objects?? Here is the configure I used when compiling php: ./configure \ --with-png-dir=/usr/local \ --with-apxs=/usr/local/sbin/apxs \ --with-bz2=shared,/usr/bin \ --with-config-file-path=/usr/local/etc/apache \ --with-curl=shared,/usr/local/bin \ --with-dom=shared,/usr/local \ --with-zlib-dir=/usr \ --with-xml=shared \ --with-xmlrpc \ --with-expat-dir=/usr/local \ --with-gd=shared,/usr/local \ --with-gdbm=/usr/local \ --with-gmp=shared./,/usr/local \ --with-iconv=/usr/local \ --with-iconv-dir=/usr/local \ --with-imap=shared,/usr/local \ --with-imap-ssl \ --with-interbase=/usr/local/firebird \ --with-jpeg-dir=/usr/local \ --with-mcrypt=shared,/usr/local \ --with-mhash=shared,/usr/local \ --with-ncurses=shared,/usr/local \ --with-openssl \ --with-pic \ --with-sybase-ct=shared,/usr/local \ --with-ttf=shared,/usr/local \ --with-wddx=shared \ --with-xpm-dir=/usr/X11R6 \ --with-zlib \ --enable-dba=shared \ --enable-dbase=shared \ --enable-filepro=shared \ --enable-inline-optimization \ --enable-ucd-snmp-hack \ --enable-shared \ --enable-shmop=shared \ --enable-sockets \ --enable-track-vars \ --enable-wddx \ --disable-static \ --disable-rpath \ --sysconfdir=/etc \ --without-freetype-dir \ --without-pear \ --with-tiff-dir=/usr/local \ --with-pgsql=shared,/usr/local \ --with-ldap=shared,/usr/local \ --with-kerberos=/usr \ --enable-xslt=shared \ --with-xslt-sablot=shared,/usr/local \ --with-snmp=shared,/usr/local \ --with-pdflib=shared,/usr/local \ --with-pfpro=shared,/usr/local I have entries in my php.ini (extension_dir set and extension=pfpro.so) that are supposedly correct. Any and all thoughts/suggestions are appreciated. Kind Regards, Steve Ose stose@nycap.rr.com