Welcome to LQ!
I just finished copying a DVD with K3b. It works.
You need to provide more information when you make a post.
Please read
How To Ask a Question so that you'll get better help.
The person in your other thread did not mean that you should
double-post, but that you should HAVE posted this question in
the Linux - Software forum at LQ.
After you read that LinuxAnswer, you'll know more of what
to post in this thread to get better help. The k3b page tells
what other apps you need to go with it in order to burn DVDs.
Have you read and checked to see if your system has them?
How did you attempt to copy a DVD?