Chosen Solution
The Supadrive in my iMac reads and plays CD’s with no problem, but when I try to burn a music CD, either by disk image or from an iTunes playlist, it goes though the motions, but at the end, after a longish period “finishing”, it tells me there’s a medium write error.
First see if the disk will play. Next you can different brands of disks, Geta optical cleaning disk from some place like Radio Shack (overpriced) or order it on line.