Andrew I think i do transcode DVDs into AVIs with AC3 5.1 sound in it and the 5.1 sound works in the result file (or so i believe?!?)!
I'm using some older version of transcode. It gave me some trying and testing and i think the result is what i wanted... The parameters make transcode to copy the audio stream untouched from DVD to avi. Result Avi is big though. I'll try to look up the commandline and post it later on or tomorrow. Martina