This is what I have done for my backups....
1) Update firmware of the DVD burner. (!!!! important).
2) Use http://www.imgburn.com/
and set the book type option.
3) Burn at speed *4 (or lower).
4) Use specific DVD medias.
5) Don't put my finger on the DVD media before burning (...).
Anyway I still get 20-30% junk, but is due to a problem with the iso file or badly patched iso files (If I do a 2nd, 3rd copy... same problem).
No problems with the version of GTA laying around