Burning a dvd with closed caption

I have a work video that was made of interviews of various people close to our work, done by us with a video camera; so no copy protection exists on this dvd. But we had closed captions or subtitles put on in order to make it more accessible to the hard of hearing. I have Nero 7 and when I copy the dvd to another disk I lose the captioning, any ideas how or what I should do to fix this? Thanks in advance.

-I also have PowerISO, I just want to make and exact duplicate of the original, and retain the captioning.

I know you can make a 1 for 1 copy of it using ImgBurn. It’s a very good burning program.