Try using a good cd laser cleaner, Allsop make a good one as this will clean off any dust/muck resident on the lens. Also, if it only happens on certain CD's, try cleaning them too; existing damage (scratches) can be minimised by gently refinishing the surface using a clean soft cloth and a small quantity of T-Cut (similar to brasso). Also be aware that due to the cost involved a professional repair is often uneconomical, so replacement might be better if a quick fix doesn't work.
Jules
June 2004