Cd Drive Doesnt Recognize Some Cds


I have a g3 ibook running on os x. When i pop in a music cd- burned or otherwise- the cd icon pops up on the screen and itunes opens. But when I put in a data cd- like a burned cd with files on it, the cd drive makes noises as if it is reading it, then stops and nothing happens. The icon does not appear on the page and i cannot open it. The same thing happens with DVD's. How can I fix this problem? thanks