No audio was captured when Burning VCD using Nero 6

I am trying to burn some VCDs for my baby using Nero 6. I have CD-RW and DVC combo drive by sony. the buring process was successfully. when I played either on my computer or VCD player, No sound. the pictures were fine. just no audio at all. Please help me, I have been trying for 3 months but can not get it done. I email the Nero support and they asked me to upgrade the firmeware which I did, but still did not work. then they stoped supporting me. if anyone can help me, I really apprciate that!