double sided dvd audio sync problem

[bluey43]

I have a 2 sided dvd which i wanted to back up into one dvd. I followed chickenman's tute on joining double sided dvd's. so far so good.

When i checked the audio, the first half is in sync, but the second half is out of sync.

so all i have now is a set of vob files that has the audio out of sync half way through the movie.

Can anyone please help or suggest a way i can fix this?

Any help would be greatly appreciated as i am going crazy not knowing what to do.