about the DVD...?

I bought this on DVD from Amazon a little while back, and when I was checking through it, at two points (about 1:11 and 1:20), both of which also seemed to be around chapters, it seemed to skip about 7 minutes while on fast forward. It seemed to play okay (in other words, the movie was still on the disc) when I rewound back and on normal play, but the skipping was disconcerting. Has anyone else had this problem? Is it a flaw with all copies? Any help will be appreciated. Thank you.