No audio after ripping to Generic/AVI

I am trying to convert my dvd ISO file to an AVI so I can play it on my MP4 portable player. I go threw the steps and everything seems to be working, but soon as its done there is no audio. Video looks fine but audio is just silent. Can someone tell me what I’m doing wrong, or give me the DVD FAB steps for successfully converting a movie to AVI. Thanks in advance for any help.