problem burning backup of dvd made from mpeg2

[hippietreehugger]

I have captured video from tv with an external device as mpeg 2 , edited out commercials and saved again as mpeg2. Used roxio to burn dvd and it plays fine and quality is great. Problem is when i try to make a copy of that dvd it will skip and freeze. I now know i can edit and save as dvd, then burn and be in true dvd format which i can copy with no problems. I can't tell any difference in quality either way but i can can fit more video on a dvd using mpeg2. So my question , is there a reason i can't copy a dvd made from mpeg2 files????