DVD and MP4 movie times not matching

[jnyfive]

I've tried searching but can't find an exact query.

I looked at the movie times of a DVD and the converted MP4 and notice the movie times don't appear to add up. For example, at 1:30 on the DVD the same scene does not appear on the MP4, its another scene. Also, the full move lengths don't seem the same. Is there a reason for this or could it be my settings causing this? The video looks exact, the aspect ratio the same, etc. Just the times are off.

Thank you.

[Baldrick]

How big is the difference? several seconds?
What do you convert to mp4 with?
Does it happens with all dvds?

[ronmaz]

frame rate? Use MediaInfo on both files and check the details.

[Hoser Rob]

There may be a short disclaimer or warning or something of the sort that appears at the beginning of the video if you watch it on DVD that's stored in a separate file on the disc. And the dvd ripping software is ignoring it.