Are you using those blue CD's? Because you shouldn't, they're inferior. If you've had the empty CD-ROMs for a long time they may likewse have deteroriated. Note that some CD players are obviously more fault-tolerant than others (in particular, older ones tend to be less so). So if you have a slightly faulty CD and a slightly faulty (or simply old) drive the combination may fail even if the CD plays elsewhere, or the drive plays other CDs.