so I'm watching the dark knight rises on my computer. It is the IMAX version so it had scenes that go from 1:2.35 to 16:9 and back. I watch it with SRT subtitles that I play with FFDShow. I want the subtitles to move when the ratio changes. I've played with the auto-crop function but it does not work, it crops the movie to the wrong ratio and stuff.... I know that "stop scan after (ms)" had to be 0 and that I have to select "vertical".

Does somebody know what I have to fill in at "tolerance"?

(I'm sorry for my bad English, I'm dutch )