Do the discs that you've burned play in other CD players without a problem?

Have you tried any other burning software? I haven't had problems with Nero, but if you have other burning software installed, it might be worth burning a CD & seeing whether the same problem exists.

Are you using CD-R or CD-RW discs? Try using CD-R.

Try using a different brand of CD, sometimes certain players don't seem to like some brands of CD.