[MacDV] How do I make copies of DVD Studio Pro movie?

[JUNE PARLETT]

I recently ran into a problem when trying to make more than two 
original copies of a movie I made, which I had brought into DVD Studio 
Pro 3. I thought I could just simply make copies of it, and it would 
work, but it does not work, and that means I need to find the old 
completed file, which was a QT Final Cut Express 2.0 movie, and either 
take it into iDVD or back into DVD Studio Pro. I thought that there was 
a work around, but there appears to be none that I could find. The 
movie files from DVD Studio Pro are in two folders: one called Audio 
and another called Video. No amount of copying will make the movie play 
on another DVD. I had a friend try it, and I tried it, and now I have 
lots of coasters.
So is there no other means to make a copy of a movie, which is burned 
to DVD from DVD Studio Pro, and have it actually work?

June Parlett