Agree ImgBurn seems like the business; I wasn't clear above that my 2.4 burn was done with ImgBurn on Windows. My drive has the latest 1.18 firmware on it so I expect I am ok there. I know the Master image is ok because I've used it via MythTV. I found another tool called DVD Identifier that did a quality scan on the 2.4x burned disc that came out really bad (
http://dvd.identifier.cdfreaks.com/).
Next step is better media (Verbatim).