I have burned 100s of ISOs (mostly movies and operating systems) in the last 5ish years using this setup with the most recent successful one being a Linux Distro about a month ago. This is the first time I have ever used Verbatim branded DVD-Rs though but based on the reviews, as you said, its a good brand. I have had most of them fail on burning (my last burn took 4 attempts before succeeding on the 5th. I will try your suggestion of updating the firmware. At this point I'm thinking I may have just gotten a bad batch of Blank DVDs?