I have created a dmg of the disk (compressed/no encryption) using Disk Utility and have tried to burn to a DL DVD without success. I've searched this forum but was unable to find the correct procedure. Thanks.
I'm not sure if this is true but I've read it in multiple places before (not just there) so I (just in case) never mount the image before I burn it if I want it to be bootable.
Okay, it just worked. Not sure why is failed before, maybe bad media or juju. I created a new copy of the disk with the NEW IMAGE icon, and burned with the BURN icon using the default settings.
In my web searching about this issue I read that mounting the image before burning would lead to problems.