Is it only me or what

Almost every time I rip a vob and then open it directly into VirtualDub-MPEG2 the sound gets out of sync, the more I play it near the end, the worst it is.

Is the AC3 decoder the problem? I'm using AC3ACM v0.7 and as far as I know it is the one most people are using?

Someone knows how to fix this?

Thanks!