DVD player stops the picture and re-winds to a previous track

I have a SONY DVD player model DVP-NS305 which tends to stop in mid picture and re-wind by itself to a previous track. It is usually happens with old DVD discs that tend to be scratched/worn out. However, I tried the same DVDs on a different machine and they worked fine so the problem is definitely with the player itself.
Your advise will be appreciated.
Thanks.