Decompressed *.vob file sound is not working properly

Hello, i’m new to this and would appreciate some professional help here: i’ve uncompressed scenes from a ratDVD movie, it usually saves as .vob files. the problem is that whatever i play them with or even burned to DVD-Disc, the sound is not working properly, that is: sound portions keep repeating and it’s not synchronised with the video anymore. It works properly with VLC player. i have the AC3 codec installed. what is wrong?