Audio Sync problem after re-encoding

[jweaver]

I have found 100s of overly large "TV" shows on my NAS which i am in the process of renecoding to make them smaller.

I have encountered a pair of files (2 halfs of the same show), that after reencoding the audio "slips" out of sync through the lenght of the show. at the beginning its in sync and by the end its several seconds out.

There is clearly something wrong with the files, rather than Hybrid as I have encoded many 100s of other files with no issue.

I have tried my normal techniques to get around this:

1. Passthrough Video, encode Audio
2. Encode Video, Passthough Audio
3. Passthrough Video, Encode audio without any encoding.
etc

No matter what I do, every time or method of encoding, the resulting file has bad audio sync... I am tempted to just give up on this one.. But before I do.. I just wondered if there were any tools, switches or feauture that I might not be aware of which would help in situations like this..

I know that there is little help that can be offered here and I am not expecting anything.. But just wondered if I was overlooking something obvious.

Jon