[Serusers] voicemail - /usr/local/lib/sems/plug-in//apps/voicemail.so Undefined symbol

Hi, I'm trying to run sems and get the following error: su-2.05b# ans_machine -E Configuration: configuration file: /etc/sems/sems.conf Ser's FIFO: /tmp/ser_fifo our FIFO: /tmp/am_fifo smtp server ip: localhost smtp server port: 25 announce path: /usr/local/lib/sems/audio/ default announce: default_en.wav plug-in path: /usr/local/lib/sems/plug-in/ maximum record time: 30 daemon mode: 0 (14022) INFO: run (AmServer.cpp:144): Loading application plug-ins (14022) DEBUG: load (AmPlugIn.cpp:83): loading /usr/local/lib/sems/plug-in//apps/echo.so ... (14022) ERROR: loadPlugIn (AmPlugIn.cpp:97): AmPlugIn::loadPlugIn: /usr/local/lib/sems/plug-in//apps/echo.so: Undefined symbol "_ZN7AmAudio5closeEv" (14022) ERROR: load (AmPlugIn.cpp:85): while loading plug-in '/usr/local/lib/sems/plug-in//apps/echo.so' (14021) DEBUG: sig_usr (ans_machine.cpp:56): signal 20 received it also gives the same error for announcement.so and voicemail.so It's sems-0.1.0 running on FreeBSD 4.9. I could only find http://lists.iptel.org/pipermail/sems/2003-November/000002.html which is not very helpfull. Does anybody knows how to make it works? Thank you in advance Juan