Good sound but CD unreliable

I've had this boombox for maybe a year.  I rarely use the radio, got it for playing audio books on CD or cassette.   Still use it for cassettes, but the CD starts stuttering unpredictably after playing a while, playing CDs that work fine on another player.  Don't know whether it's age or the vertical position of the CD player (pressing on door seems to restore operation).  Wouldn't buy another like this again.