Knoppmyth has been working great for me for a long time, but I encountered a problem tonight. I have been using old 8x Ritek DVDs with my box, but I recently ran out, so I popped in one of my 16x DVDs to use. The burner (NEC burner) is 8x max, so I figured Knoppmyth would burn it at 8x max. However, when the dvd is ready to burn, the log gives me something like a "this disc is not supported or unformatted" error. I don't have another 8x disc to test this with, but I'm almost sure that they are the problem. Is there any way I can set my drive to use 16x discs to a max of 8x?

Thanks.

Are they rewritable disks? If so, you need to format them before you use them.
The command is:
dvd+-rw-format /dev/dvd
(or something like that. I'm not by my box to check. Just type dvd+<tab><tab> and you will see it).

No, they are not. They are 16x DVD-R (tried both Memorex and Ritek), and 8x DVD-R have worked perfectly before.

Is it possible I just need to upgrade the drive's firmware? I'm going to try and see if that will fix the problem.

Fixed it. It was a firmware problem. If you have an NEC burner, make sure to update your firmware. All the new media I had wasn't working correctly, but its all working great now.