jacked up radio

i have the cd player for a '96 GT, the CD player is the one that came with the car. what happens is that more then half the time when i try to turn the music down it gets louder. i keep spinning the knob to quiet it but it takes a while before it seems to realize that when i do that i want the noise to get softer.

is my player shot? or is there a way to fix this? i'm not about to buy a new one till this one is totally dead, but if i can fix this it would be great.