Wrong playback direction of the car cassette player's autoreverse feature. Our car cassette adapter can only work on one playback direction, if it doesn't work on one direction try to change the autoreverse direction of the car cassette player.
Customer's car stereo not compatible with the car adaptor cassette. The car cassette adapter is not compatible to all type of car cassette player. i.e. The front loading type. If your cassette player has LINE In jack use it instead of the cassette adapter. Connect the signal lead to the LINE IN jack and to the LINE OUT jack of the CD player.