I have a NEC 3520A DVD drive. Playback/burn of Region 2 DVD' is ok, however when I play Region 1 DVDs the picture is very 'jumpy' & blocky, getting worse towards the bottom of the screen. This only affects moving images; still picture eg DVD menu is fine. Audio does not seem to be affected ether.
I can play the DVDs on a chipped Sony player without problem.
I am using the NVIDIA PureVideo decoder (4020.150)
Any thoughts would be appreciated.