Apple DVD-R media: 1x vs. 2x write speeds: a follow-up

Adding more info to our initial reports on this topic (see one and two) Bruce Strange writes:

"I archive to DVD-R every day and I've been purchasing apple DVD-R exclusively, because they write at 2x. I have several of the gray DVD-R boxes. I checked the numbers on the disks themselves and they are all of the ZM033-1913-A type. I tested a few and they all wrote at 2x using the latest version of Toast Titanium. However, I just received 'certified 2x' DVD-R disks from discmaker, and they only show as 1x in Toast. When I called discmaker, they person I spoke with said they are getting several calls a day about this issue. Apparently, there is a firmware update that is needed for the Pioneer drives in order for those discs to operate at 2x."