Originally Posted By: tanstaafl.
It almost has to be a software/firmware thing, because it will burn DVDs flawlessly, but won't even pretend to write to CDs. Well, it pretends to write, in that it says it is writing, but it really doesn't write anything to the disc.

The writer has two different lasers inside to write to CDs and DVDs as the wavelength is different so it is possible that it is a hardware fault.