Rashiki

Sounds like the drive lens is dirty. You could insert a cleaning disk with the little brushes on it to get any particulate matter (dust) that's rested on the lens. Just don't go ape and run it every week, the brushes will eventually jostle the lens out of it's magnetically supported hovering position. If you're feeling savvy enough, you could pop open the drive and use a high content alcohol on a q-tip to remove the dust, but you can't go ape here either. Too much pressure will ruin the drive, and over time the alcohol will remove the film layer on the lens.

Best bet is to use a cleansing CD and see what happens. It won't ruin it on the first try.