Car cd auto changer

I have recently bought a car with an 8disc auto changer in,the product being a panosonic CX-DP88ON and i am not able to play my cds init. It does play but starts jumping and skiping through my cds as soon as i start to even roll in my car,never mind if i am on a bumpy or abit of an uneven road. I have tryed everything in the manual that states what to do if you have troubleshooting problems and nothing as worked. It as been mounted, as it is very sturdy and secure, i have tryed cleaning it and even reseting it and all the cds i have tryed with it have been brand new, shop bought cds. I consulted the former owner of the car and they said it was working fine with them and cant understand why it is doing it. They also said that all the cds they use to play in it were all downloaded copies and they played fine. The car also is only 4years old and as very low mileage as the last owner didnt use it on a daily basis,so cant figure out what the problem could be, any suggestions? or advice of what i should do with it, would be very appreciated! Please help! thanks