It probably doesn't matter; the PAL/NTSC thing was a wild guess anyway. All I know for certain is, the firmware upgrade fixed the stuttering problem completely for me. I hope it turns out an easy fix for you too! Colin.
Hi Gau, That sounds exactly like a problem I had with our new DVD player a couple of years ago, which was (is) a Yamaha DV-S5450. A pause in both picture and sound for a second or two, sometimes with a slightly pixellated screen, occurring 2-3 times per movie on average, never in the same...