This article is from the CD-Recordable FAQ, by Andy McFadden (email@example.com) with numerous contributions by others.
If the disc is recognized but won't erase or format, see section (4-27).
One possible source of difficulty is there are different blanks for
"slow" recorders (1x - 4x), "high speed" recorders (4x-10x), "ultra speed"
recorders (12x-24x), and "ultra speed +" recorders. The disc manufacturers
had to change the way the discs were made to accommodate each successive
improvement, so older recorders don't work with the newer disks.
It is possible for some 4x-capable "slow" drives to use the "fast" blanks
with a firmware upgrade, but there is no advantage to doing so since you're
still limited to 4x recording (unless, of course, you're unable to find
"slow" CD-RW blanks).
CD-RW discs for the faster drives are labeled with a "High Speed",
"Ultra Speed", or "Ultra Speed +" logos. Make sure you buy the right blanks
for your drive.
A press release for Verbatim's Ultra Speed + 32x CD-RW discs is available