no sound ripping dvd to avi/mkv/mp4

[runLoganrun]

I'm using xilisoft ultimate to convert my dvd's. right now i'm using the mp4 format with x264/ac3(or pcm). xilisoft is cool because it supports 5.1 sound, but when i convert my movie i get nothing. I've played the dvd in wmp and it works fine, but when I convert it to an avi or mp4 I either get barely audible, or no, sound. I've used this software before and it worked great to convert to ipod format. I had a different installation of vista then though, and different codecs loaded, everything plays fine now though, aside from these conversions.

any idea why no sound?

thx,
rlr

[Baldrick]

Try instead ripbot264. I think it can make aac 5.1 from dvds in mp4 files.