Help! AC3 Audio Sync Problem

[stomped]

Have a DVIX movie with AC3 audio that trying to convert to DVD but after encoding the audio becomes out of syn as movie plays.
Orig avi is perfectly in sync.

Video stats
Framerate: 23.976
Audio: AC3/ 48000 Hz

Have:
Virtualdub: scan video stream and re-saved avi to remove bad frames.
Result :Fixed Avi with 0 bad frames. (Checked and audio still in sync when play this file.)
Goldwave: Extract AC3 audio and convert to Wave.
Tmpgenc: loaded fixed Avi as video stream and Wave as audio stream then ecode using wizard.
(I use external program, Toolame.ex to encode audio in Tmpgenc)

Result: Great quality mpeg file which bout third of way through audio goes out of sync!

Have encoded lots of movies to dvd before but not had this prob.
Please any ideas for further action!!!!

[Hardcoreruss]

Try...Extracting audio with vd save file as audio.ac3. VD will add .wav prefix. Remove this and open in headac3he convert file. Convert in tmpgenc using this newly created audio file and original video. Works for me.

[mats.hogberg]

I've found that quite often, the audio stream is not "aligned" with the video stream in an AVI file. The audio data may start "at any" point within the AVI. If you extract the audio, you get the audio stream, but if the audio is offset by 1 s in the original AVI, you understand what will happen if you mux back the audio with the video - The audio will be 1 s ahead of the video.
Either add corresponding amount of silence at the start of the audio, or somehow recreate the A/V offset (skew).

/Mats

[stomped]

thanks for the replies
I shall try extracting audio as AC3 in VD first then Headac3he.
Was wondering should that be 'Audio-Direct Stream Copy' in VD when extracting?

Stomped