Since I upgraded to the AMD64 architecture some months ago, I always had the problem that burning CDs did not work anymore. I used a command line like
cdrecord -V gracetime=2 dev=3,0,0 speed=24 -dao -dummy driveropts=burnfree -eject -data test.iso
but burning failed some seconds after the write started.
Now, it seems that I found the solution: with kernel 2.6 and udev, it is not necessary to use the device numbers anymore. Instead, the device file can be used directly, like
cdrecord -V gracetime=2 dev=/dev/cdrw speed=24 -dao -dummy driveropts=burnfree -eject -data test.iso
This also seems to influence the way how cdrecord and the kernel interact, because the write process now does not abort anymore.