checking bad sectors on a DVD

A DVD that I recently purchased seems to have bad sectors.
Specifically, when I play it in a DVD player, there's a certain point
where the video becomes all garbled and remains that way for a
noticeable number of seconds.

I'd like to get a new DVD, but I don't want to rewatch the whole thing
to verify that it is free of bad sectors. I'm thinking that perhaps
there's some software I could use to scan for bad sectors for me?

I could probably use CloneCD to do it, but the problem with that is
that I'd have to waste a dual layer DVD-R just to get a coaster (since
CSS encryption would prevent me from actually copying it). So... any
ideas?

 

For checking CD/DVDs I like CDCheck-

CDCheck is utility for prevention, detection and recovery of damaged files
with emphasis on error detection. It can check each of your CDs and DVDs
and indicate which files are corrupted. CDCheck reporting features tell you
exactly where the problems are. CDs can get damaged in a number of ways, so
the program helps you determine whether your data is safe before it's too
late. The program also provides a comparison option that lets you select a
reference directory on your hard drive (or some other device). CDCheck
ensures that the contents on a disc match those in the directory, and
effectively alerts you of differences. Besides that CDCheck supports
creation of CRC files which provide extra safety that files on your CDs are
still exactly the same as they were. In addition to CD-ROMs, the program
can be used with all other local or removable media (disk drives, floppy
disks, ZIP drives...) visible by the operating system (Windows Explorer).

http://www.elpros.si/CDCheck/

Freeware
1.35MB

 

But link clearly states does not work on DVD's

 

You need to go back and read again!
Also it is normal practice to quote part of the post that you are replying
to, so at least someone will know what you are talking about.