Q When I burn playlists totalling greater than an hour or so in length to CD-R using iTunes, an error message is shown and the burn stops short of the end. I am using 52x supermarket media, and have found that dropping the burn speed from ‘maximum possible’ to 8x seems to enable completion without error. Is this a problem with iTunes, the media, or my optical drive?

A This is most likely to be a burn error resulting from using marginally compatible media at a non-optimal burn rate in a drive that is a bit grubby. The more of those factors that apply, the greater the chance of it occurring.

The simplest remedy to try first is cleaning the optical drive, using a gentle cleaner that does not involve the use of free fluids, which could damage the internals of your Mac.

The quality and suitable burn speed of unbranded cheaper media is also less reliable, so paying a bit more for a reputable brand can help by making it perform more consistently.

If you still encounter errors, cutting the burn rate often helps, but certain media and drive combinations may prove more reliable when burned at their maximal rate. Perhaps it is simplest to arrive at a proven and trusted combination of media and speed, and stick to it.

Updated from the original, which was first published in MacUser volume 27 issue 17, 2011.