iDVD 4: Assets re-encode when burning a Best Quality project that you have already burned

If you want to burn multiple copies of a project at Best Quality, do this before you quit iDVD. If you quit iDVD and then open the project again to burn another copy, the video will need to be re-encoded in Stage 3 again. This happens because all MPEG files that are created in Stage 3 are deleted from the project's MPEG folder when you quit iDVD.

Alternatively, if you quit iDVD but have the project already burned to a disc, you can make a copy of the DVD-R by following the steps here.

A note about copyright
This software may be used to reproduce materials. It is licensed to you only for reproduction of non-copyrighted materials, materials in which you own the copyright, or materials you are authorized or legally permitted to reproduce. If you are uncertain about your right to copy any material, you should contact your legal advisor.