Subtitles out of sync playing back in Kaffeine

I’ve got vob files from a video dvd disk and these files have integrated subtitles. I want to watch these files with separate subtitles, but subtitles go out of sync almost immediately and by the end of the film subtitles are only in the middle. I tryed those files on another platform and the problem wasn’t present. Kaffeine is the only video player I use in SUSE.