Missing first 15 to 20 minutes of dvd copy

I am missing the first few minutes of some dvd copies. For example the movie Hitch and chicken little. Not the first time this has happened. I am using dvd shrink. Using reauthor mode and selecting movie only. Able to see beginning of movie as i backup using dvd shrink but after movie is burned the beginning of movie is missing. Is this copy protection? :confused:

this could be caused by the reauthor process. you may try super dvd copy to get exact copy from it.