For some time, when selecting the CD write test option, I have been receiving reports of multiple CD write errors but without any obvious playback errors. This is occurs on two computers and was not corrected when I installed the latest CD Burn software.
There are 2 types of CD errors that can occur - those that are detected and corrected at the time of burning, and those which are fatal, ie the disc is unplayable.
The write speed influences the error rate, particularly if you write at or near the maximum write speed of the disc, which for economy discs is often overstated and can affect a significant proportion of a whole tub/pack of discs. I always used to write at half the maximum speed of the disc and not get any errors.